my advice from experience - throw the tint kit away and get it done professionally. unless you've got alot of experience, a windless working area free from dust and small particles, and a ton of patience you'll end up with creases and air holes and tiny lumps of crap under the tint that all show up as white bubbles. you've got alot of curved glass to do - take all the problems above and multiply them by 10!! iirc the rear screen is curved 2 ways, which means you've got to use heat to shrink the tint film to shape - too much heat tho and the tint will shrivel.
you mention security - have you got 'security' film or 'tint' film? if its tint film then it doesnt stop anyone from smashing the glass, and its also easy to see through if you get up close to it. its also illegal to tint your front side windows more than 35% (im sure its 35% but if im wrong please correct me) and the police can pull you over and tell you to remove the tint on the spot and give you a £60 fine. and yes some police cars do carry light meters to see how much light travels through the tint.
if you still want to tint it yourself then make sure the glass is clean. then clean it again. scrape it clean with a razor blade, then clean it again. ANY SMALL SPECK OF DUST no matter how small will show as a white bubble!! remove as much trim as possible from around the window. work in a garage, with the doors closed, and make sure the floor is swept out. pour water on the floor all around and under the car so any dust left will stay in the water and not become airborne. once the tint is on the window and you've squeezed most of the soap/water out from under the tint, use a hair dryer to dry and shrink the tint slightly. if your rubbing a squegie over the top of the tint to remove soap/water underneath make sure the tint is nice and soapy/wet or it will rip.
best bit of advice - buy a roll of tint from halfords or somewhere and try tinting a window BEFORE you try with the kit. its ALOT harder than you think