So what is the issue and how would you like it to be different? By ‘amendment’ do you mean a subtle tweak to the proposal or do you mean change it to something substantially different? If the former, you can propose an amendment from the floor at the AGM.
Amendments are OK and would be allowed at the meeting if they are sufficiently minor. EG. you can’t have an amendment to insert the word ‘not’ and completely negate the intent of the proposal. On the other hand you can move an amendment that does not substantially alter the intent and effect of the motion (IE minor tweaks). For example, let’s say there is a motion to declare the driveway a no stopping zone. Perhaps what was really meant was a no standing zone if the issue is people who park and block the driveway for hours at a time, not people briefly stopping to let out a passenger. Then an amendment to change ‘stopping’ for ‘standing’ would be OK.
In all such things it is generally better to talk to the EC and others before the meeting.