Trouble with Howdens 200mm pull out base cupboard

Hello all, new to this forum been lurking a while, just registered have a bit of a bit of a problem, I'm part way through fitting a Howdens integrated handle kitchen, got all the base units in and the majority of the doors etc, but have grief with the 200mm pull out cupboard door fronts, the base units came with the runners pre-fitted, just need to attach the doors, but there are no spikes on the back of the door for the brackets (except the normal hinge arrangements) there's a square shape plate at the top and one at the bottom each with 4 holes to attach the door to the pull out cupboard hardware, been through the Howdens intsallation manual a few times checked every page and there's no reference or instructions on new spike holes for the pull out cupboard, been back to Howdens and was greeted with a check the manual mate !, I know I could just give it a go and try and align it up, but I cant even hold the door up to the unit and mark the position of the plates because the worktop is on, just wondered if any one else has had this issue and could point me in the right direction, would rather not make too many holes in the back of the doors with trial and error.

Thanks in advance, would appreciate any help, FYI I've fitted kitchens before but never fitted pull out base units

 

Thanks for the reply will give it a go