Changing wipers

The wiper is one of the most important items on the printer.

It is the ONLY item DESIGNED to actually touch the nozzles on the bottom of the head.

It is CRITICAL to keep the wiper clean, as the ink and threads that can dry up here can be pushed up into the nozzles or actually cause damage to the nozzles over time.

Replacement varies with use, the wiper should be replaced when it become warped, distorted, very soft or very stiff.  Usually every 3-12 months.

The wiper is flexible and has a slot that hooks over a tab in the wiper holder.

Normally, these get pretty soft over time and will just pull out.
Stiffer ones may require a very small blade (jewelers screwdriver)to push the 'holes' away from the hooks. Too much force here will distort the holder, so be careful.
 

Kevin at Valentino Design uses this method:

Drawing courtesy of  Kevin of Valentino Design in Glendale Arizona.