You could most likely do this without buying a service kit at all.
Bigger question is do you plan to change the door locks as well? Otherwise you could easily lock yourself out and not have a door key.
The ignition cylinders themselves are held in by active retainer, meaning you would turn the ignition to acc (with key) and and push in retainer to pull it out. Once it's out it's just a few steps to disassemble (pm me for details.)
The cylinder has 8 wafers inside, I would remove the wafers and take account of what you have and try to re-use wafers. (All wafers are stamped with their number which is 1,2,3,4,or 5.). It isn't that big of a deal if you only put some wafers back in, this would make it easier to key alike and the little bit of security you loose is not going to make a big deal at all.)
This is definitely a doable thing, let me know if you need more help.