To revamp = to 're-vamp' :)

[Tamara]

Hi

So we decided to revamp the whole system from top to bottom.

[Conchita]

'Patch up' has a negative connotation that 'revamp' doesn't have. To patch up is to repair something more or less, perhaps even provisionally, while to revamp is to improve the appearance of something (maybe something that is a bit old-fashioned) and suggests a complete change. 'Renovate' is a good definition.

Then there's 'vamp up' something, which is, make it more attractive or exciting, but that's a different story.