Cut it out and then iron out all the wrinkles
Line the fabric up as good as you can and then pin the 3 sides of the pillow and start sewing away. Now, if your lucky and have a sewing machine you can get this done pretty fast. I on the other hand can't seem to justify such a big purchase at this point because 1.) I'm a cheap ass and 2.) Until I start doing more projects that require sewing I can gravy train off my sisters OR get over it and hand sew it like I did this
Start sewing at the corners where the fabric is folded and meet in the middle of one side, leaving a small space big enough to fit your hand through open
Use that hole to turn the pillow inside out. Then I used Aleene's fabric glue to glue on the heart. You could sew it, but the felt was very stiff, thick, and intricate. I knew it would be too hard to hand sew. I let it dry for 24 hours before stuffing the pillow and then sewing up the open space.
Here it is all done
Not professional grade, but not too bad for a newbie at hand sewing.