Hi Dave,
It's somewhat hard to give an answer, not knowing how you have built it. I'm assuming you used wood glue to glue the strips, and I am hoping you taped the edges of the forms. If you did, the glue won't have that much purchase on the forms. I'm also assuming that hull and deck are still on the forms and that you have cut out the cockpit.
If you used an external strongback proceed as follows:
Beginning from the cockpit, drill a hole through the nearest forms on one side, insert a stiff wire hook and pull hard towards the middle. They should release.
Since I haven't used an internal beam, perhaps someone else can help you better. It depends on how you fixed the forms to the beam and if you can loosen then from the cockpit side to slip them back.
Otherwise you will have to pry the two halves apart and wedge. Work your way around the periphery lifting and wedging a little bit at a time. As you work your way around insert the wedges further as you go. At some point the glue will release the forms. It is probably better to inert the wedges at the forms themselves and not between forms.
I don't think heat will soften the glue. If it isn't waterproof you ccould try soaking the form edges.
Hope you succeed.
JohnK

: Hello All,
: I am building an Outer Island and I used the stapleless method. The problem
: is now I have a deck that seems to be glued to the forms, I tried bashing
: the inner forms out and the deck started to come apart. The garage is
: unheated here in Minneapolis and I have a shot at a heated garage, will
: heating it up soften the glue?
: Thanks
: Dave