Is there a way to remove options like SETUP,SERVICES,Dash etc from UI? Help for my Dad

I bought my Dad this for Christmas and he is loving it but there is one problem. My Dad (has Parkinsons) has trouble with the remote control like he always accidentally hit the wrong button and sometimes scroll all over the menu selecting the other options and gets lost. I already figured out how to fix the remote by removing some buttons lol but when you scroll all the way up or down you still end up at the other options :frowning:

I looked into how to create a theme but it’s too difficult, I was wondering if I could just edit the existing default theme by deleting some lines in there. If anyone can help I would appreciate it. thanks.