Replacing time capsule with new one

Put your old TC back into the network. Assuming it still works.

You plug your new TC into the old one with Ethernet.

Open the airport utility on a Mac and you should see the new Airport device.. as Other WiFi Devices (1)

Click on that and it will start the setup wizard.

Click options instead of going straight through the setup and choose to replace existing device.

Here is a good example from Bob Timmons with screenshot.

Re: Help, want to change my actual network configuration from Airport Express to Time Capsule

If your old TC is dead.. you will need to plug the TC into whatever is your main modem or modem router.. and do a full configuration from scratch. If you are having trouble seeing the TC when you do that.. you have something wrong in the configuration.. we strongly recommend NOT using windows version airport utility.. and even the Mac version is less than great.. iOS version on ipad is about the best.. it is free download from apple store.

Otherwise tell us exactly what modem you have and how you are trying to do the setup and on what computer/OS.

Assuming that the old Time Capsule is still operational, If you will leave the old Time Capsule connected to your network for the time being, there is a special option in AirPort Utility to Replace an existing device. This will automatically transfer all of the current network settings on your old Time Capsule to the new Time Capsule, and then reset your old Time Capsule back to original default settings.

If you decide to do this, connect an Ethernet cable from one of the three LAN <--> ports on the old Time Capsule to the WAN "O" port on the new Time Capsule, click the WiFi icon at the top of your Mac and then click on AirPort Time Capsule under the heading of New AirPort Base Station.

When you click on AirPort Time Capsule, that will start up the AirPort Utility setup "wizard". It will take a few seconds to display a screen that might look similar to this, except that you will two Time Capsules pictured.

Click on the Other Options button at the lower left of the windows and another screen will appear that will look like this, except that you will see a Time Capsule pictured:

Select the option to Replace an existing device, and follow the prompts.

When the set up of the new Time Capsule is done, power off the new Time Capsule and old Time Capsule, physically replace the old Time Capsule with the new Time Capsule, and power up the new Time Capsule, and you should be all set.

Did you......?

Open System Preferences (gear icon on the dock)

Open Time Machine

Click Add or Remove Disk

Select the "old" backup disk (which might be named "Data", unless you changed the name of the disk)

Click Remove Disk

Close the windows

Restart your Mac

Open System Preferences

Open Time Machine

Click Select Disk

Select the new destination Disk (which might have the same name...."Data"....as the disk on your old Time Capsule

Click Use Disk

Then, try a backup?

As you might imagine, it makes things easier if the disk on your new Time Capsule has a different name than the disk on your old Time Capsule. You can use AirPort Utility to change the name of "Data" to something else if you wish.

In the example below, you can see that I have changed the name of the disk to Backups. The other drive.....named Test Drive.....is a USB drive connected to the USB port on the Time Capsule.

I found that the time capsule that I am replacing did not transfer any old backups to my new one

It was not designed to do this. Only the network settings, passwords, etc are transferred over. The data on the old time Capsule disk remains unaffected.

I'm thinking this shouldn't be a problem if I am doing new backups now on the new one and I keep the old one for awhile just in case an older backup is needed for some reason.

Correct.

I assume I can put the old one back in the network if need be.

If you followed the instructions that LaPastenague and I provided, the old Time Capsule has been reset back to its original factory default settings, so you if you want to access the backups on the old Time Capsule, you will need to connect it to the new Time Capsule using an Ethernet cable connection and set up the old Time Capsule again with a different name using the AirPort Utility setup "wizard".

It is unlikely that you will ever need to do this, but at some point you might want to erase all the old backups on the old Time Capsule and then use it for additional storage or sell it to another user.