I replaced mine this summer by cutting them to fit, minus about an inch. Then I slid, at an angle, as many as I could into the channels. I sarted with the boards on each side, working to the middle. (You may have to wiggle them across, into place.) The final two in the middle, (I think two), I inserted one end in the channel and put a jack, like a floor jack, about 1/3 of the way from that end. I raised the jack pad, with a block of wood on it, until the board was pointing upward toward the "unchanneled" end. I walked on the board until it bowed down in line with the mouth of the channel. I as I stood there, my wife let the jack down slowly until the board was in the channel and the jack was down and clear. The boards will bow enough to get them in. Just be careful and watch your fingers.