Hi,
I just finished doing mine yesterday, I bought the kit off amazon its XXR tools 21 piece master ballpoint set think it was around £65.00, you have to modify some of the bits to get a good fit but if you got a grinder its not that difficult to adapt the bits in the kit, its not a simple job but no near as difficult as the Haynes manual suggests, just give a really thorough clean and de rust and apply plenty plus gas or similar I didn't even have to use any heat and my only joints were pretty rough, at first you think they won't go but all at once they start to move and before you know it they are out, you then have to give the receiving bores a good clean up get all surface rust gone and make sure there's no burrs in there you want it all nice and smooth, plenty of copper grease in bore and on the new joint and then press back in, making sure the joint is square in the bore as you go.
I was impressed with my tool and glad I didn't buy the £499+vat Sykes version, or pay out the £900+ that I was quoted to have them replaced, good luck with your repair just take your time and care adapting the bits in the tool kit and you'll be fine, also on U tube there's some videos by an Australian guy called Mike Murphy that cover this repair using the same or very similar kit, title is 'swearing and skinned knuckles' well worth watching before you start.