Since you're either savvy enough or foolhardy enough to attempt a brake conversion yourself, your garage is probably already stocked with all the tools you'll need to assemble your disc brakes. But putting your new brakes on is not going to be the hard part. Taking off your old brakes will probably pose the biggest challenge.
Maybe your bolts haven't fused and rusted, and maybe all the lubrication has managed to not dry up and blow away. If you happen to be that lucky, then a socket set and a torque wrench will certainly do the trick. Just in case you're not that fortunate, it's probably best to prepare yourself for some resistance. So make sure you have some penetrating oil, a sledgehammer, a hacksaw or an acetylene torch on hand.
There are dozens of factors that can complicate your brake conversion -- all depending on the make, model and year of your vehicle. You may need to remove springs, shocks, and possibly even an axle in order to get this job done, so make sure you know what you're in for before you get too far in the process.
As for putting the new brakes on, conversion kits have everything you'll need to put your new brakes together, but if you're shopping at the local junkyard, you'll be taking brakes off the donor car in addition to your own, so make sure you're tooled-up for another possible struggle.
Front- and rear-brake assemblies are not interchangeable, so front and rear conversions do differ slightly. Read on to find out what's required for each, and what complications you may encounter.