Here are the basic tools I use. I carry these with on trips, too. I've changed quite a few tars in parking lots and other people's garages using just these tools or similar. Bought the two large arns at a shop in OH several years ago when the "didn't have time" to help me. Changed out the tar with a take-off from their trash in their parking lot.
Each of my bikes has at least one "core remover" valve caps. Metal caps are better than plastic anyway.
A common mistake is to NOT soap up the old tar. This makes it much easier to break the bead.
Two arns, tip up, and the third thin one in the center, tip down to get it behind the tar bead and help the soap distribute. (BTW, at home I have a tub of "real" tar soap, available at most auto parts places.)
Once the soap soaks in, lever the bead down 'til it breaks.
Once the bead is broken on both sides, it's just a question of using the arns to lever the tar off the rim. I do this by myself regularly. The example is a very stiff Bridgeston BT020F. The trick is DON'T worry about scratching yur rims, no one is ever gonna look at'em closely anyway. :D
When installing the new tar, closely match the arrows. Note this tar is "backwards" to soap up the correct bead before installation... Once soaped, flip the tar over to install the first side. Usually no tools needed for this part.
Once soaped up, it's relatively easy to install the first side. The second side has to be levered on. I use the C clamp to hold the initial edge below the rim.
Now just the effort to get it all 'way 'round. Here the new tar is just ready to "pop" into place.
I recommend installing new valve stems. Available in packs of 5 at auto parts store, or probably for free at any tar shop. Be sure to get cores with the RED band. They are specifically for higher temps than the black bands.
The new tar in this case is an Avon Storm, but the technique works with virtually any tar. I balance static, using a rod and pair of jack stands. I don't bother to balance when "on the road" and it's never presented a problem.
Remove the label first, it weighs enuff to impact the balance. :D I have sticks of sticky lead weights, purchased from NAPA. But, I don't bother to balance when I change a tar on the road. Never been a problem at reasonable speeds. Hope folks find this helpful. If I'm in yur area when ya need to change I'll be happy to help. :DYou may have to search out a tar shop to set the new beads and air up the new tar, but I've done it (with luck) using my tiny 12VDC compressor. Sometimes it works...