The first thing you want to do is try to get the craft brewers in the state to endorse your proposal. You can also try to get the distributors on board although they may be tied to one of the BMC corporations and unwilling to break ties. You will need their support because the legislature isn't going to take it seriously if the regulated industry in question doesn't care. Once you have tentative agreements in the industry then you can get petitions passed around the state with actual signatures of OH citizens.
Then you need to draft the legislation and have your industry contacts approve the proposed language and provide firm endorsements. Ask if they will write endorsement letters explaining how it would be good for the state. Then submit the proposed legislation, endorsements and petitions to the offices of all the representatives and senators in the state. Then call, call, call to find reps and senators who will support the bill and introduce it.
It's going to be a long, hard battle. Raising the ABV limit on beer in the state isn't much of a pressing issue and you'll likely encounter resistance from liquor, wine and big brewery businesses and industry groups. You may have to keep submitting it through several legislative sessions.