If it were me, I would leave it alone. First, assuming that you don't have a disconnect outside of your house, (since you only have 3 wires coming in, I'm sure you don't) you will have to schedule a disconnect with the power company so that you can have access to your meter socket with it De-energized. You could then pull the wires coming from your meter socket to the panel out of the conduit. Cut the conduit above the breaker panel. loosen the panel from the concrete wall. You can then slide a spacer or whatever behind the panel then reattach the panel. Then you can put an offset on your conduit to make it reach out to the box, pull in the wire, make your connections and call the power company to reconnect you.
Fortunately, all of your wires come in the box at the top. As you move the box out from the wall a bit, you can move it up some too and your main wires coming in from outside will still reach. Looks like the most you would have to buy is an offset for your conduit and maybe some screws to fasten the box to the wall if you don't already have them. Oh, and you should get some anti-ox inhibitor grease for your connections since your wire is aluminum. It probably already has some on them, but I always put more on.
When you tighten the connections on aluminum wire, you should tighten, then loosen, then tighten, then loosen, then tighten, etc. Just like using a torque wrench. If you don't, with heat and cooling, the aluminum will become loose under the connectors as it is temperature sensitive. This procedure will keep this to a minimum or eliminate it all together. I have done it for years and it works well.