easy, dad and my brother did it last year. I must say it was real hard to find one the size we wanted. we wanted to be able to pass shore power cables etc through it. I think we got them from Defender but not sure. Used a hole cutter to do the job and dremel to do finish work. mask off the outside and trace the cut out then use the hold cutter took about 3 holes then used dremel to smooth off the points. bevel the edges install and drill holes, counter sink the holes and seal it in place. if there is air gap between cockpit liner then fill with spray foam then epoxy micro baloon puddy.