Your best bet is to find an old, longish, straight slotted screw driver which is not too wide. Beat it over a vice about 1 inch back from the end to make a slight curve in it, so it looks like a staple lifter. Beat to about 30 degrees, no more. 45 is too steep.
The strips often seem to be best started from the bottom, and you can use a smaller, regular screwdriver to get it started. Then insert your tool in and carefully pry as you get to each nail. If you go slow and yield if you feel it wanting to bend and break instead of lifting you should get all 4 off OK.
As they are nail gun brads, you can't re-use them. Clip them off flush with the wood. If you don't have a power nailer to re-apply the strips, get small brads and pre-drill all your holes or you will likely split the wood.
...and all this work from one errant ball toss........ well, at least you won't have to figure out what to do this weekend. :^ )
It's all about the music...