What program to read codes of plugins?

[Besotted]

I have a box server where I need lots of plugins. The plugins work all fine but some of them must be edited directly in the code. I notice all the titles with the suffix ".jar" I cant read propably, it says my text editor doesn't support the file. What text editor shall I download and how do I apply it so that the file actually opens in the editor?

 

[DuckyProgrammer]

You'd need to decompile the code with something like jd-gui, and recompile it using something like IntelliJ. I wont go too far into this as its advanced and against the terms of use for most plugins.