Can't reinstall from time machine backup! Help?!

Hi,

I recently had an issue running a video game on my macbook pro; and after contacting their tech support they explained it was not yet supported on macOS Catalina. (I had been playing for years prior to updating to Catalina).

So, I decided I would fully reinstall to a backup I had made on an external hardrive using the Time Machine feature. The backup I had selected was prior to updating to Catalina. I got to about 3/4 of the way through the process and it said "An error occurred while restoring from the backup".

I read a few articles that mentioned looking at the log window to find any "critical errors", and I noticed "error -34" and then text relating to something in a folder (Note: I'm not good with these kinds of tech issues). These articles then recommend to plug the external hardrive into a working macbook, "mount" it to the termal, and then remove the problem file/folder that way - and it should work after...but I dont know how to do that.

If anyone has experienced this kind of issue or knows anything that could help I would greatly appreciate it! I would love a very simple step by step of how I can fix this problem. All I would like to do is access the time machine backup prior to Catalina and reinstall.

Thanks!