Easiest way to remove fence staples is with a angle grinder. Cut the staple. Cattle panel and 2x6 can both be used.I think one should always plan to make things easier to take apart, at least for hobby farm- and garden-related structures. We reused the cattle panel shelter we built for the sheep as a garden trellis 12 years later. I couldn't reuse most of the wood because it was attached with fence staples (I had to chop it off with a reciprocating saw). Would've been nice to have extra 2x4s in this day and age.