[General] How do I get this if I want to make modifications to the code?

[Zireael07]

The standard way is to specify it in Cargo.toml:
glsp = "0.2"

but what if I want to modify the code after getting it?

[Fleabit]

Thanks for your interest!

You would need to fork the fleabitdev/glsp repository. GitHub provides some instructions here.

[Zireael07]

Fork the repo, and drop it in my existing project you mean?

A bit of a pity that cargo.toml doesn't put the code somewhere accessible after getting it...