Here are the steps for an 00 or 01. The 02 and newer have a different seal carrier and can be done another way. You can update to the 00 and 01 to the 02+ seal, BTW. It'll save you a LOT of time if you ever have to do it again.

Remove the seat and tank. Clean under the tank area well so nothing will fall into the motor in the following steps. Drain and remove the radiators (drain bolt is an 8mm headed bolt under the left headpipe) and hoses. Lock the crank at TDC on the compression stroke with the crank locking bolt. Unhook the head oil line from both ends. The lower one can be a pain to remove with the pipes in place but is doable.
 
Remove the valve covers. Remove the left side rubber tank mount. Remove the waterpump cover and impellar (you may have to work at the impellar a bit to get it off). Remove the decompressor cable. Remove the rocker box cover screws and lift it off. Remove the camchain tensioner bolt (watch for the spring!) and remove the entire tensioner assembly. 

Lift the cam shaft as much as you can and remove the WP seal. You may have to rotate the seal so that the cut edges are on the sides (00, 01 only), depending on the style of seal carrier. You should be able to remove it easily with your fingers. 

If you were going to do the cam bearings, this is where you'd pull them. There are a couple of methods for doing that. Let me know if you want those details.

If you're installing a new decompressor stop bolt and nut (use red loctite), you can do that anytime after you get the rocker box cover off. Make sure you stuff rags around the cam chain openings so that if you drop anything, it won't go into the motor internals.

Use all new WP seal parts (carrier, 2 seals, 2 orings) and install it using the KTM "bullet" tool, KTM part number 590 29 005 010 which is about $5 from www.cyclezonektm.com . You can also wrap a piece of plastic, etc around the end of the camshaft before installing the seal, too. The point is to avoid wrecking the seal on the sharp groove. 

BTW, the inner seals are a VERY tight fit and it's very easy to mangle them trying to install them in the carrier. How do you get it in then? Contact Old Stroker. He has the 'TOOL' and he presses them in for individuals and dealers all over the US. Email him at OldStroker@sbcglobal.net 

Reinstall the chain tensioner assembly and then put in the tensioner spring and bolt. Clean all the gasket surfaces and apply a coat of anerobic gasket maker, like Loctite 515, to rocker box cover and install. Set radial play on rocker arms before tigtening. NOTE: You might want to practice installing the cover a couple of times before you actually apply the 515. It's a tight fit but it does work.

Set valve gaps and reinstall valve covers. Put impellar assembly on and install the cover with a new gasket. Install oil line, radiators, etc. 

Drain oil and clean the screens after a short ride just to flush anything out of the motor. 

You'll need 1 seal carrier, 2 inner seals, 2 outer orings and a WP housing gasket.

See these KTM service bulletins before you start, as well:
http://pws.chartermi.net/~jejb/pictures/ktm_valveclearance_bulletin.jpg
http://pws.chartermi.net/~jejb/pictures/ktm_decompressor_bulletin.jpg
http://pws.chartermi.net/~jejb/pictures/ktm_515_bulletin.jpg