Surface Mount Ironing Board

I need to delete some CMS to a board and then solder them again ... how can I avoid the burna

You need a very fine tip for your soldering iron. If one is not available for your iron, you must replace the iron. To remove single-member constituencies, get a SMD removal kit from Digi-Key. It is a fusion weld very low point and special flux. It dissolves the existing solder, then the device is detached without damaging the card.

Clean using soldering wick, then clean with solvent.

Apply flux to flow from a pen, then solder the new device using welding very thin and fine tip of your iron.

Depends on the game. If you talk of 1206, 0805, 0603 resistors and capacitors. I heat one side, then switch to the other side and again and usually come right away. If you have two soldering irons, you can use them as a pair of pliers and heat both sides at the same time and just pick off the game. Using solder wick or desoldering station to clean.

If you want to remove a DIP or PLCC, you can try to solder wick, very lucky and patients. I used a hot-air reflow that heats up all the pins at the same time and just pull out of the chip. But if you do not have access to such a system, I suggest going ahead and the size of the chip, the PCB is larger and cut and remove each pin.