The instructions with Ezyguide are very good, you have to move boat back on trailer so it over hangs the ezyguide rollers by around an inch, also you fit it at home without the springs to get correct location, then drill holes for brackets, fit the brackets without the rollers, then take boat down to ramp, launch boat, fit rollers and springs, reload boat and check, also when its fitted you on only back trailer in until rear roller is in the water, too deep and boat will just float make ezyguide less effective. ezyguide are cheapest through Bias, cheaper than online shops.