You will have to grind of the head of the rivet to release the QR.
There are rebuild kits available from Porkchop or BMXworks (maybe other places too). I guess you could source a rivet elsewhere but the one in the kits is shouldered which make it easier.
The new rivet is formed using what is called a 'rivet snap' (3/8 should do it), simply a punch with a concave end, they are very cheap. It is not difficult at all, you can do it with a hammer like in metal work class. Probably best to use a press for more control.
