YouTube has videos on soldering techniques, for this very type LED project. So, maybe check there.
I learned tons, about soldering, on YT. NASA even has soldering tuts, on there! It is easy to spot the folks that don't know what they are doing. Just move on, to the next one.
Plus, there are a lot of DIY work-around solutions, for tough problems, with limited specialty tools. Heat gun, hot plate, clothes iron, homemade reflow oven...
See "Mr. Carlson's Lab," for how to easily make a special tip, for the pistol-style soldering irons, that dumps a lot of heat, to a flat surface, in a hurry.
I made my own DIY reflow oven. It works, well enough.
See if there is a MakerSpace club, in your area. They often have great equipment, for the members to use. And, expertise, too.
Isopropyl alcohol and a static-free brush (An old toothbrush would be okay, here, because the component has been removed.) will help with cleaning the board. You can get it at most any pharmacy. Get the highest percentage of alcohol, that they have... 99%, but not all stores have it.
Do you have flux and solder paste (not solder wire?) If not, read up on those, too.
Please remember to post your solutions, to help the next guy... I would like to know what you do, myself.