how do I access the wiper assy? 73 dart

If you have A/C, you're in for more of a project than non-A/C. If the arms are still attached at least to one end, take some photos of how they're attached, so, you get them back the same way. Having to do it all over again because you got a link backwards is a real bummer. Pull the entire wiper transmission out as an assembly and replace ALL the bushings. I like to lube and spin the pivots completely around too fully free them up too. Some of the earlier models you could rotate the base 180 degrees, which sometimes helps with wear, but, I'm not sure you can do that your year. Using a vice and some sockets the right size can help with installing the bushings. Good Luck!