Usually you just need to be available by telephone on the day of the meeting to discuss any matters that your creditors may raise.
People will have upto the time of the meeting to submit votes deciding if they want to accept or reject your IVA. The purpose of the meeting these days is just to have a cut off point.
Ideally I prefer to read through these with the individual and to then get a copy signed confirming that they are understood and accepted. The advantage of this is that there is no ambiguity in the future over what was in the original proposal and how any modification changes the proposal.
If you are in any doubt about a modification ask the IP to explain it to you in simple terms that you understand before accepting it.