my 2 cents
turn off the power to the vfd.
wait 15-20 minutes to allow the capacitors to discharge.
use canned air designed for electrical components.
we use Sprayway - clean jet 100 - 10 oz can
its non flammable
the can has a part number of SW-805
you WILL need the following.
safety glasses with side shield.
face shield
proper ppe clothing.
proper hand gloves.
the ppe is in case the caps are still charged and some trash is dislodged and shorts out the caps.
you will also need this for when you re-energize the vfd, definitely then.
remember, safety first.
james