the easy way but not the best is to try and adjust the hinges,various hinges have various adjustment apetures whic usually need a allen key,by far the best method of correction is to remove the panel/glass and to toe & heel the door it simply means supporting the door leaf with the unit fixed between the beads ,if you click on the link below it will take you to a site of a pvc manufaturer which explaines the way to toe & heel ,if you were in liverpool for a small charge i would call out and fix the door ,hope this is of some help any futher quries e-mail me
regards kev http://www.doorexpress.com/information/fitting/door.asp
kevinkeith2001@fsmail.net, January 2009