How to disable the read-only attribute from a field?

Hi everyone!

I try to migrate our code from version 7 to the new version 8 and I´m stopped with a Read-Only issue,

Some products have defined questions catalog which must be answered by the user. These answers are save into a custom table (all persmissions are correctly set). 

The problem is the user cannot set an answer because the textfield is Read-Only.

Any idea how I can solve this issue?

Thank you!