That is a solder bridge, and it is one of the easier things to put right. It does not mean the board is ruined, and you do not need to take anything apart. Leave the board unpowered until the bridge is cleared.
Put a little fresh flux on the bridge first. Flux is what makes the solder let go and flow where you want it, and it makes everything below far easier. Then use whichever tool you have:
Desoldering wick. Lay the braid over the bridge, press the iron down on top of it for a second or two, and lift the braid and the iron away together once the solder has drawn up into it.
Desoldering pump (solder sucker). Heat the bridge until the solder is properly liquid, then lift the excess off with the pump.
Neither to hand. Reheat the bridge and drag the tip away across the pins and off the edge, wiping the tip on a damp sponge between attempts. Surface tension usually pulls the two joints apart on its own.
Check the result with a magnifier, or photograph the board with your phone and zoom in. You are looking for two separate cones of solder with clear board between them, each one covering its own pad.
If the bridge will not clear, or a pad has lifted while you were working on it, message us here, or email [email protected], with a close photo and we will talk you through the next step.