Has anyone had the pleasure of replacing their radiator on a 1.8 n/a A3?

I have a slow leak at the bottom right hand corner (As you look at the front of the car) and need to top up the water every couple of days... Thought about trying RadWeld but am worried about damage that it can do to the small pipes and the potential lack of flow to parts of the engine.

Is there any problems that may occur witht the replacement such as air locks and/or special tools that may be needed...

Any help would be greatly appreciated...