reverse engineering exe code

A friend (and yes he exists) has asked me what I know about reverse engineering a exe file that was written in VB.

The question is:  How can it be done and what tips?

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What version of VB is it? If it's 4.0 or below it's possible to get the code I think, but with VB5 (and VB6?) you can only get the 'design information' like how forms and controls look like but no code.
There are no decompilers for VB5 and VB6.
You can take VB programs down to their raw ASM code with a disassembler, such a W32Dasm. However it will be mostly lots of calls to the VB dll. The is also a decompiler called 'DoDi's Decompiler' which works for VB 2 and 3 - although all your variable names will be changed. If you are trying to recover source code from a vb4/5/6 executable it cannot be done, however if you are trying to change some functions, it can be done fairly easily with a hex editor, a disassembler and a debugger.

Debugger - Softice
Disassembler - W32Dasm
Hex Editor - HIEW or Ultra Edit

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Visual Basic Classic

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