Free .NET decompiler that allows variable renaming [on hold]

I would have wanted to avoid asking a newbie question like this one on StackOverflow, but I'm having some problems in finding a (free) .NET decompiler that allows me to rename variables and methods. I'm currently doing some reverse engineering of malware, more specifically ransomware, and I need to understand how they work.

I came across the discussion .net decompiler that allows renaming fields, and I'm trying ILSpy and Reflexil, but I'm not able to rename variables, only methods. Is there any way?

Thanks in advance to anyone :)