Need help trying to set up new Seagate Barracuda SSD to replace old Macbook Pro hd

I just received my new Seagate Barracuda SSD 1TB SATA hard drive and I wanted to use it to replace the stock Macbook HD since it's on it's last limb. I've tried using the disk utility, but every time I try to restore the new hard drive as the current HD, I keep getting an error message saying I can't do it because I have read-only permission. When I get into the disk info, I don't have the ability to change my own permission to read-write. I have High Sierra OS and from what I've read, they disabled the ability to make it read-write. Is there any sort of work around for this? I've tried for a few hours now searching and calling Seagate's customer service, but I can't find anything specific to my issue. Thanks in advance.

I should add, this is the message I get whenever i try to use disk utility:

Validating target...

Validating source...

Source volume is read-write and cannot be unmounted, so it can't be block copied.

The operation couldn’t be completed. (OSStatus error 19.)

Operation failed…