I found this carrier quite straight forward to assemble, and it only took a little while to complete.
Very easy to fit to the towbar and very secure once you've tightened it up sufficiently. it easily held 11 stone of me standing on it. The carrier does weigh a little bit, so some people may need assistance to hold it whilst tightening it up. I'm certainly no Swarzenegger and i managed it on my own. Fits onto the towbar by a simple 'cup' bracket that has a single bolt holding it. The bolt has a gnurled surface that allows it to be finger tightened, though you the need to use the supplied 19mm spanner (or one of your own) to tighten the bolt fully. Once again i found this to be quite easy.
Relatively easy to fit the bikes to.I found i needed to put one arm through the frame holding the bike, whilst i put a strap round the upright on the carrier and the bike frame to hold it in place. once in place the straps could be threaded around the wheels on the carrier to hold it more securely and then adjust the upright strap to ensure everything is held firmly. for peace of mind, i tend to add extra straps round the upright and both bikes.
The carrier is tiltable to allow access to the boot/hatch, though i understand that this may not be the case on all cars, especially some of the people carrier types. I've used it on a Vauxhall Vectra, Skoda Octavia, BMW 3 series and Ford mondeo with no issues, if in doubt as to whether yours will be ok, best bet is to try one before buying if possible. The tilting mechanism is a little fiddly, you need to loosen two nuts (with plastic grips on them) and then rotate the J shaped bolts out of the way, then tilt the carrier away from the car.
All in all i've been very pleased with the 9502 and am now considering the 9503 as the kids are growing and their bikes are getting bigger