I may not be on when you get back, so here is your problem.....
Here is the plug you have---->
Part Details - GE Water filter bypass plug, part number: WR02X10173
When you changed filters, at one point you had to get an adapter for the new filter (white) to fit in the filter head recepticle that is this part----->
Part Details - GEH Ge smartwater™ refrigerator filter adapter, part number: ADAPTER
So, for you to use the bypass plug you have, you need to remove that adapter, it unscrews just like the filter does.
Hope this helps