You will need a spring compressor with a fairly deep reach to get down onto the spring caps. One designed for modern 16v engines.
A Haynes manual will tell you most of what you need to know. Bear in mind that you want to keep the hydraulic tappets, valve springs, collets, etc. in the same fitted location when you reassemble if at all possible. You can either remove one valve at a time or remove them all and place all the bits for each valve in a small plastic bag and label it.
You will need something to pull the stem seals out. Maybe a suitably sized spring that will locate over the neck of the seal and grip it or failing that you can get a special type of plier. Be very careful not to nick the hydraulic tappet bore!
While you've got the valves out, clean them by putting them in a drill and rubbing with emery cloth, wire wool, etc, then lap them into the head with a sucker on the end of a stick and some grinding compound. Clean all the compound off when it's done. (you can check for a good seal by shining a very bright light under the valve head or by filling the combustion chambers with paraffin with the head upside down and seeing if any leak).
Reassembly, as they say, is the reverse of removal.

Kevin