How do I create a good summary of each act of this play and analyze it?
A good way to make your own summaries is to read carefully, and make a note everytime something happens. Then, look over your notes and decide what was the most important event or revelation of that act. Then, expand upon those events in two ways-- one, explain what happened and what it means to the story which is the summary. Then interpret what you think the events mean in a more general sense and you've got the beginnings of an analysis. Good luck!
eNotes has some really good summaries and analyses of The Birthday Party. Check out the links below, I think you will find exactly what it is you are looking for.
Link #1- character analysis
Link #2- summary of Act One
Link #3- summary of Act Two
Link #4-summary of Act Three http://www.enotes.com/birthday-party/act-iii-summary