Need help with mod updates.

[Doom Demise3]

This may be a stupid question, but I need help.

When I start up voltz, in the chat log, it says:

You have 5 mod(s) that needs to be updated: Atomic Science[0.3.8] Basic Components [1.2.6] Electric Expansion [1.4.6] ICBM [1.0.5] Assembly Line [0.2.7]

An updated version of Railcraft is availiable: 6.15.3.0

It is clear that I need to update these mods but I don't have a clue how to do it. If anybody knows, please leave a reply.