Youri le god

Hi there,

I've aquired a beaten up old Buescher Aristocrat. It has had some considerable damage and work done (very badly!!) to fix it. I am considering using this as my test horn to practice soldering on. I have lots of experience soldering electronics (I do all my guitar repairs myself) but have no brass soldering experience. I've done some searches here and on TH for soldering info. Is the process anything like plumbing (or am I being dim!)?
The first obvious problem on the horn is that when you push the tuning slide fully in only one of the joints comes flush (the top one) and there is about 1cm of tubing on the lower portion protruding. It looks (to the untrained eye) like it needs unsoldering and redoing in the correct position. Can anyone offer any advice on equipment and processes?
Thanks
Des