Removing paint from wood: lattice
Lattice is really cheap stuff. It's probably easier to just get new lattice and rebuild the gate. Or, for a simple fix, get a wire stripper wheel for a power drill and take at it. Get as much off that comes off easily and then cover it all with quality primer.

FYI, if a lot of the wood has been weathered for a while, it's going to be a chore to get primer to stick to it without a lot of sanding. Again, might be easier to replace the lattice al together. You can also usually find synthetic lattice that doesn't require any painting.