i know now how to fix this
i hope this will help someone in the future
step one: click editable mesh
step two: select the part of the model
step three: detach that part
step four: on the modifiers click unwrap uvw
step five: click edit
step six: fix the uv map to your liking
step seven: convert it to editable mesh by right clicking and pick "convert to"
step eight: attach it back to your model
and your done