How to edit .dll

I have .dll with its source (that later i will need to attach to main.exe) and i need edit it to make some customs work.how to start editing it?

with ollydbg
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what about :

there is a .dll file (already compiled) and there is its original source code(not yet compiled)

after making some changes to source code , how to easily compile all those code files into a one single .dll file ???

i doubt you can do that with ollydbg , and to get microsoft visual studios just for this one single time is ridiculous.

what to do?