If i open tower to clean out dust will i get shocked??

A tower fan should not be opened at all. (It’s unsafe to do so, and may damage your fan.) Every two to three weeks, simply use the brush attachment of your vacuum cleaner on the tower fan intake grills to remove lint and dirt, or use a can of compressed air to blow off dust from inner fan blades. That’s it! Your clean tower fan is ready to be plugged back in and get back to keeping your home breezy.

Source:
https://www.lasko.com/periodic-cleaning-keeps-electric-fans-operating-at-their-best/

The easiest way to to use pressurized air. Buy a can or use compressed air.

Hi, a can of compressed air is what you need, can pick them up at most hardware shops, can be purchased online also-http://www.ebay.co.uk/itm/2-x-Compressed-Air-Duster-Spray-Can-200ml-Cleans-Protects-Laptops-Keyboards-/370750150980?pt=UK_Computing_Sound_Vision_Cleaning_Equipment_Kits&hash=item56526e5944
A few blasts should loosen any debris, then simply run the fan to remove any remaining dust.

Clean your air tower fan by using small paint brush and wet rag(s). Turn off power and unplug, then open the fan by using screw driver either flat or crossed type. Eliminate dust and dirt using paint brush and rub it with wet rags. When disassembling put screws in box and be observant so that you'll able to assemble it later. Do not wipe motor with wet rags only the propeller, front back cover and so on.
Good luck.

Open the grills and use a long stem tipped with cloth dipped in kerosene to lightly clean the dust. Then use a similar arrangement of dry cloth wound on it to wipe clean the moist dirt. Repeat the process and you will have a clean blade. Use a jet air blower to assist you , use face mask and do it out in the open.
Helpful ?

I would suspect it needs a good internal cleaning. The accumulated dust will cause the computer to overheat. Disconnect all cables and take the unit to a place where you can clean it. Remove the side panel and then with a can of compressed air or an air compressor blow all dust out of the unit. Pay special attention to the heat sink on the processor. Make sure you clean the power supply fan. Be sure and not touch any internal components without first grounding yourself to the chassis. It is best to do this outside as the dust will fly everywhere. You should clean the inside at least once a year. Merry Christmas.

Go down to a local shop and ask them if they could blow out the fan for a few bucks with their compressor air supply.

Open up the side of the tower and you will be able to see the fans. You most likely have dust/hair in one of your fans or one of the fans is going bad. You can clean it out with a low pressure air nozzle or dust can.

Use compressed air to blow the dust etc. out of the unit.  You can purchase a  can of compressed air from Home Depot or Lowes, or Google "compressed air in a can."  Just make sure you clean the unit outside to keep the dust etc. out of your home.  

there are two screws on the back of ur tower for each side supporting plate .remove the side plate which is on the other side of ur motherboard.then just blow out all the dust with a air blower.