Creating QFN-24 3.5mm x 3.5mm

Download Van's .fzpz file.
Change the .fzpz extension to .svg.
Right-click IC and select Edit.
In PCB - File/Load image and find the now .svg labeled Van part.
Click on the pin labels in the top right box and make sure the correct ones highlight in the drawing.
Go to Meta and change the Properties from QNF to TSLP.
File/Save as new part, and add a -2 to name.
Close Edit.
Close fritzing saving the bin.
Open FZ and select part, and in Inspector select package TSLP and it should change.