My suggestion is to get it done at the workshop and get it re-tuned with the MUT/PDT2000 after that...
If you want to DIY, just remove all the hoses, remove the 4 main screws bolting the TB to the intake manifold.
Then use petrol/diesel with a brush to remove the excess dirt deposits on the butterfly plate and inner parts... Be sure not to wet the sensors, if you are confident enough with a voltmeter, you can remove the stepper motor and after you clean it, you need to get a certain voltage to make sure u got the right step or else ur tuning kong like s**t... My suggestion is to leave it and just be careful when cleaning it... most workshops do that anyway...
Remove the idle screw and clean that as well... then replace it till the end and loosen it about 8-10 twists...
when you place everything back (be sure not to overtighten or you'll screw up the bolt's teeth), then start the car, and tune the idle screw till you get to about 750-800rpm, or whatever you like as an idle la... 900rpm is a nice one to have as you get to start off the traffic lights nicely (if you are using AT)...
hope this helps...