Well, I managed to blow up the PIC in mine, I was putting the wires on the back of the PCB to attach the two extra switches, instead of soldering wires to the through holes which go back to the PIC and ground, I put the ground wire on raw +12v, so first time I pressed the push button switch the PIC died, i’ve been back to Specsavers since so it will not happen again
The way I replaced the PIC was to cut down the legs where they go into the plastic of the IC, I do this on each side with a scalpel or new Stanley blade, once they are all cut, the plastic of the IC will come off leaving all the legs standing up still soldered to the PCB, it is dead easy then to unsolder each leg carefully whilst holding it with SMD tweezers.
Once they are all off, clean the PCB with some solder wick and Isopropyl alchohol, and put some SMD rework flux on the pads.
Then, making sure the PIC is the correct way around, drop it onto the pads and get it as close to aligned as you can, a magnifier helps massively.
Once it looks ok, solder one of the corner legs down using the thinnest solder you can find, and a good iron, I use a Metcal iron with a needle tip.
Check again that the IC is the correct way around, and the alignment is good, then if you want put some more rework flux on the IC and PCB.
Then it’s just a matter of going along the legs soldering them in, again use really fine solder, and take your time.
If you get a blob between pins, don’t be tempted to use a solder sucker to remove it, the jolt it makes when pressed will cause either the legs to bend or the track to come away from the PCB, use solder wick to remove the excess solder that forms the blob.
Once they are all soldered, clean the PCB with more Isopropyl and check with a magnifier for any shors between the pins and you should be good to go.
SMD construction is quite easy and nothing to be worried about just take your time and don’t use too much solder, using leaded solder is actually easier than lead free as it flows better.
Good luck with it.