The brake bridge will be a nightmare. Well, unless you can find someone who will take it on. Getting them off is easy.
What bike do you have? a PK Ripper or a Ripper? they are different.
The headset should be pretty easy. You can calculate the OD of a 1" headset, then simply buy a sheet of alu in the correct thickness to wrap it (cut it with tin snips) and then press it in. I did that in a 1997 Jad Sherman I was given from a sponsor, but only had a 1" front end.
I remember a guy bought a 2008 Quadangle and had the lugs removed and a plate welded on and said it was a nightmare.
What you could do is switch out the V brake for cantis, which appeared on early PKs.