hey If I wanted to increase or change the hard drive in my mcbook pro how long it will take the service in apple store?

Do you have a bad hard drive or are you just looking for an upgrade in size or to an SSD? An Apple Store will only replace a defective drive with another one of the same size and type. An Apple Store does not perform upgrades nor do they use third party parts. An Apple Authorized Service Provider may upgrade the drive to a larger size or install a third party SSD. You will need to contact them directly to see if they can provide you with any estimates on how long the procedure (aka repair) will take.

Many recent Macs (especially 2016+ laptops) have non-removable SSDs so no upgrades are possible. If an SSD is failing, then Apple or an AASP will need to replace the entire Logic Board.

Depending on the exact model Mac you have it may be relatively easy for you to replace/upgrade the drive yourself.

What is the exact model of your Mac? You can get this information by clicking on the Apple menu and selecting "About this Mac" or by entering your serial number here:

https://checkcoverage.apple.com/

@Grant good point. That is why I am opposed to universal apps (yes they are convenient, but they are a waste of bandwidth, time, & storage) since it is an issue especially when working from home. I'm so glad I only need to use macOS for work, as my own personal systems are so much easier without macOS even when performing installs over the Internet.

Well, you can either delete files you no longer need or move space hogging movies, photos, videos, etc. to an external hard drive.

You need 35 GB of empty space for the download and install. You should also always maintain a minimum of 15 GB of empty space for the OS and system to function properly - if you allow the space to be filled, your computer will simply stop functioning and it will be very difficult to get files off at that point.

Interesting. Typical Apple to do things the most complicated and inefficient way possible (sorry I've been struggling for two days to install Bug Sur which is required for my job where it is failing with cryptic errors).

HWTech--

I think there is "one more thing..."

When you run Internet Recovery, your Mac creates more that 25 RAM disks to store temporary stuff. This is supposed to leave your boot drive free to be erased or repaired.

But what if you want to Install Big Sur? The download is over 13.8GB, and if your Mac has only 8GB RAM, RAM disks are not large enough to hold that. Have we seen that you commit to "which Drive" for the Install BEFORE you begin the Download? Or is Internet Recovery blindly trying to cram 14GB into less than 8GB of RAM disks, and failing?

Thanks, I was not aware of that!

Sure. Don't upgrade.

If you can download the Big Sur installer, then you can try creating a bootable macOS USB installer:

https://support.apple.com/en-us/HT201372

After creating the USB installer you can delete the "Install macOS Big Sur" app from the Applications folder and empty the Trash. Oh, that reminds me make sure you have emptied your Trash. You can also boot into Internet Recovery Mode using Command + Option + R to access the Big Sur online installer (again make sure to delete the app from the Applictions folder first to free up 12GB). I highly recommend having a macOS USB installer just to be safe even if you attempt Internet Recovery Mode.

You can also go into each of your web browser's privacy settings and delete their cache which can free up a lot of space sometimes. Also boot into Safe Mode which will also delete some temp & cache files from macOS. If you have the requisite 35GB of free storage space you should be able to install Big Sur from the USB installer.

Also make sure all of your backups have completed since the boot drive will retain snapshots of deleted data until the backups have all been transferred to the external drive(s). If your backups have all been completely transferred to the external drive(s), then you can check to see whether there are any remaining APFS snapshots that may contain the deleted data:

https://derflounder.wordpress.com/2018/04/07/reclaiming-drive-space-by-thinning-apple-file-system-snapshot-backups/

Before attempting the upgrade to Big Sur make sure to have a good backup just in case something goes wrong during the upgrade or if you find that you have issues (or dislike) Big Sur you can go back to your current setup with the older OS.

If these suggestions by @babowa & myself do not help, then you will need to contact an AASP to see if they will replace your drive with a larger third party drive assuming your Mac has a replaceable drive (not all AASPs will do this). If you have a laptop with a replaceable/upgradeable drive, then it is fairly simple to perform the upgrade yourself by getting the replacement SSD from OWC where they include the necessary tools and instructions (including videos).

FYI, you only provided us with the version of macOS used and not the exact model of the laptop. If "About this Mac" doesn't show the model, then enter your serial number here:

https://checkcoverage.apple.com/

There is a really interesting (and diabolical) issue surrounding upgrading from Bootable USB-stick Installer.

A user discovered experimentally that doing so appears to requires the larger, 45+ GB free space.

My guess about why is that you can not take advantage of already installed macOS components on the built-in drive to give you the lower required space, because you are booted from the USB-stick Installer.