Can't remove using Unity Editor, it is necessary for the development of the game.

I have a problem with the UNITY EDITOR which I can not fix no matter what I try. The company I work for has bought a kit which has its own functionality, however, the kit is directly integrated into the unity editor, and I cannot remove it without breaking the whole build. Then again, I cannot build the application because Unity constantly pops up and says that a script is running (already obvious that its #Unity_Editor or using UnityEditor). Even if I could remove it, it would be borderline impossible, it is called in more than 640 places in the code. I am in desperate need of some help.