Cut the radiator tube(s) and pinch off.

 

Better yet pinch it and the put some solder in there and do a pressure test.

 

 

Technically, yes. Otherwise, a replacement will only set you back $100-$300, depending on brand/quality.

 

clean it good with water and acetone before welding, it may not look nice afterwards but it works.. depends how thin the aluminium is. definitely doable with intercoolers..

 

I wouldn't bother repairing it, not worth the risk of repair failing, spewing coolant and overheating which could quickly kill your engine. If budget is a concern, you can pick up an aftermarket OEM replacement for around $100~150 (Rockauto, etc.) or if you have the cash, get a Koyo AL dual-pass radiator (basically a drop in fit) for around $300~350.