AYou will need the long shank 6mm hex bit to get the cam housing off, a spark plug air hose adapter to pressurize the cyl at TDC to hold the valves shut, compressed air to pressurize the cylinder, a suitable valve spring compressor, more than just 8 new valve stem seals in case you mangle one, and LOTS of patience.
This was the exact job that led to the destruction of my original engine. You must plug the 4 oil return drains in the head so that you do not drop any valve keepers down into the engine, because after they finally decide to come out, that's where they will make every effort to go, and those drains do not drop directly into the crankcase! Use shop towel plugs big enough that there's no way you can leave them in there if you get side tracked.
You will want some sort of way to measure the installed depth of the seals, as they slip onto the end of the guide and they fit so tight that they require driving them on with a hammer and suitable tool (13mm deep socket worked for me). They also absolutely must be driven straight or they will probably leak! It is easy to tap them too far, which will compromise their sealing ability by spreading the sealing lip out. There is a step moulded in the inside of the seal which should be flush with the valve guide. They are virtually impossible to remove once installed, so you absolutely should have extras (made that mistake, too). Buy the dark red colored vitton seals. They last much longer than the black ones that come in the victor reinz kit. The valve springs are extremely heavy, so it is a nightmare getting them released without a good valve spring compressor. The cheap overhead claw looking one with the crank knob will work, but it is a miserable thing to use and will not compress far enough unless you get the tangs jammed into the valve coils as close to the head as possible. I don't have the picture on me now, but i have seen a 928 guy use one of those overhead lever type spring compressors meant for rocker arm valvetrain and just cut a short piece of ~1/2" pipe with a bolt hole drilled through it so it can be attached to the head using the cam housing bolts to act as a substitute rocker arm shaft to lever against. It looked like a much nicer setup. I was ready to put that screw type compressor through a wall by the time I was done.