If the Si5351 were to be replaced, I would just cut off the legs flush with the chip using a scalpel or similar. Make sure to only press down until the leg is free from the chip, not all the way down to the board. The FST3253 legs could be cut off with a small sidecutter. Collect the pins with the soldering iron and clean up the area with flux and solder wick/braid. Drag solder to fix the new one, lots of flux.
Daniel Ekman SA2KNG