How do I un-make it?

[ghost]

I installed it using make but later found out that it wasn't the solution to the problem I was trying to solve, and now I get ERROR: ld.so: object '/path/to/libgtk3-nocsd.so.0' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored. every time I open the terminal / enter a command.

[ByJumperX4]

make uninstall (assuming you did make install because make just compiles it, it doesn't install it