Be prepared for them to argue that they can keep your child SAFE without a 504 plan.
While that may be true, your child also deserves the same educational opportunities that his classmates get-- and that is why he needs a 504 plan. He is getting a 504 plan because he qualifies for one. Not because he "needs" one. Do NOT confuse those two things in your mind.
If they are going to follow the law, it's very important that you let the horse pull that cart.
1. He qualifies under Section 504 because X, Y, and Z.
2. Because he qualifies, we must write a 504 plan that includes the means through which is educational access (and yes-- safety-- but only because THAT TOO, is a barrier to his access) is guaranteed. It must spell out who will do what and when and how. Both prevention and response, and "avoidance" in terms of curricular shifts or accommodations.
You can do it!! Stay strong on point one. Get that IN WRITING before you discuss the need for particular accommodations.