yes you can,but not easy ,first you will have to find out how thick it is as there are various sizes,if like you say theres a hole mesure from outside to inside,then find a panel you like,you can order a panel from north east panels if you don't know where to get 1 from.the next step is to take your old panel out,first try and take the black rubber gasket from outside around where the door meets panel,don't worry if it won't come out because some doors don't have a removable gasket,now its time to take the beads out,you can do this by using a small wallpaper skraper or putty knife,I use don carlos knife but are expensive to buy,try and get scraper inbetween the bead and door not bead and panel then lightly prize the bead out until it starts to come out,start at middle of longest bead then work your way around until all beads have been removed,take panel out replace with new 1,now you have to toe n heal your door so it dosn't catch the bottom of your door,you place a packer(the peices of plastic that should fall out of your door when you take old panel out) on bottom at the hinge side then place a few at top on lock side untill door is level,place rest of packers around your door from where they fell out,replace your bead and if came out the gasket,job done,good luck on your repair.if you have any probs visit my website at www.sdwupvcrepair.co.uk and use my contact page to e-mail me.
shaun
February 2008