cleaning a psu

hey i want to clean my psu.
i can see its full of dust by looking at the small holes and the fan is not spinning any more.
but if i hit the fan with a pen or stick it will start going but slowly.
i heard that you can get hurt if you touch the capacitors inside the psu.
i tried cleaning it with canned air but i cant reach in it much so i cant clean it much.
i also heard that you should let it off aleast a night to get rid of electric discharge.

i got one can of canned air and is that all i need. do i need any thing else to clean the psu?
any thing that useful that wont damaged the psu would be helpful.

Those capacitors will hold a charge for as long as weeks, they will not usually dissipate overnight with out being discharged. If the fan is failing I would suggest just replacing the PSU if you can afford it, the PSU is the heart of the system.

Well the fan has been doing this for about 2 years now.
Its a ten year old computer so i dont want to spend money on it.
I use it for some gaming (mainly starcraft and star wars games lol) and internet.
Is there a good full guide of how to clean a psu.

If i type the numbers on the psu sticker on google will any thing usefull come up ?.

oh ya if i do clean the psu i should wear groves right? just in case if i touch a capacitor
if i touch the capacitor can it damaged it ?

If you really want to know my opinion, from what you have revealed of yourself I would say that you have no business poking around inside the PSU. But if you persist, only remove the cover and blow it out, anything that needs blowing out can be accessed with the top removed. Do not touch anything inside, you don't need to in order to blow it out. If you are going to do this, you are going to do this with the power cord removed from the wall receptacle, right?

lol yes am going to do it with the power cord removed from the wall receptacle lol
i opened the computer heaps of times so if i didit do that would be really hurt or the computer wouldent work
so i wouldent be posting this