You woudl use LiveCycle Designer to do it......but be careful if there is any code on the 2nd form you may break it when you combine the two forms. Open the two forms in Designer, then go to the 1st page of the 2nd form. Hit Ctrl-A to select all objects. Then copy and paste into form1. repeat for each page in form 2. Doing this will change the strucure of the 2nd form so check that all code still has proper references.
Paul