The flex tubes I assume. If the old tubes are one piece ( not split), removing all the cables and lines is a pain. Getting them back into the new tube can be a real bad pain.
Take pictures of how the services are positioned in the tube as well as a lot of pictures of how the services route into and around the engine.
After you disconnect/unbolt, unclamp all the tubes and cables, measure the amount that each extends past the end of the rigging tube so that you can match those lengths up later. That will make the final connections easier to do.
You may find out that you have to pull out one line/cable at a time until there is enough space to pull the rest or a group. Install the softer things first since it is hard to push them through a packed tube. The harness and connector should probably be first. The last parts should probably be the battery cables since they are relatively stiff. The control cables are really stiff but if you can't remove the clevis hardware, they tend to get caught on other things. Dont try to get the cables and tubes all the way into the rigging tube, just enough to be able to pull the whole bundle later. Oh, I forgot to mention, after you disconnect/unbolt, unclamp all the tubes and cables.
I use a solution of dish soap and water in the tub the parts to help them slide both for removal and reinsertion. If doing two motors, do one motor at a time so that you have the other to reference if things get confused
The amount of 'fill' in the tubing is a big factor on how hard the job will be. On my 2 stroke Mercs there are many tubes in addition to cables and the rigging tube if really stuffed.
If you think it's going to be tight, pull a thin cord or two back through the rigging tube as you remove lines to use as a drag line to pull the stuff back later. Each time you use the drag, attach another length to the far end so that you always have at least one spare cord to pull.