What i did was get some 50gr and 100gr brass shaft inserts. Started with the 50's and used a little hot melt glue to hold them in. As soon as they're in the shaft dunk it in cold water to cool the insert as you don't want it heating your shaft up.
If you want the inserts out to put 100's in, screw a field point in and heat that until the insert loosens. The field point will transfer just enough heat to the insert to loosen it.
When you've got the insert in the shaft, get a load of different weight field points and start bareshafting with them until you find the right weight. For example... 100gr insert with 225gr field point.
Once you've got that, get a broadhead of that weight. So for 225gr you can take a 125gr glue on Woodsman and glue it onto a 100gr adaptor and screw that into your 100gr insert.
Hope that helps.
Stan