Yeah, #4 bit and on some of them you may need to put a 1/2” or 13mm on the nut even though they are serrated. Leave the crossmember bolted to the C bracket on the frame on each side. Also, you don’t have to remove the screws on the back edge of the skid that bolt into the support bracket. In all there’s 6 hex head bolts and maybe 8-10 #4 Philips.