Changing the seals is pretty easy, most Marzocchis are built the same, unscrew the top caps and take off the bottom nuts and the whole lot will come apart, the stanctions will then slide out of the lowers and the seals can be levered out, the oil seal is usually held in with a snap ring so this will need to come out first.
Keep everything really clean and in order (i used a load of kitchen roll when doing mine), knock the new oil seals in carefully with a large socket, put the forks back together the way they came apart pouring fresh oil in through the top caps.
My Shivers can be seen stripped in this thread if that helps
http://www.retrobike.co.uk/forum/viewto ... 6&start=15