how do i connect kicker to main engine?

hi folks,i just bought a new merc 3.5 4-stroke kicker and want to hook it to my 60hp merc main engine.now,the old kicker was a 2004 6hp nissan 4-stroke and it has a metal bracket,{the one you carry the engine with}so i was able to make a alum.plate{see crude attachment} and bolt it to the bracket and connect my threaded remote steering arm to it.the bracket on the new merc is plastic and i'm a little reluctant to drill holes in fear of weakening the bracket.any ideas would be greatly appreciated.ps,i really don't like the steering arm that connects to the rear of the engine,with clamps.