Removing the engine from the Magna is a relatively easy task.  In my opinion, it's easier than trying to install the carburetors without the technique I've developed.  So how is it done?  First of all, think of it as removing the frame from the engine, not the engine from the frame.  This will make things a lot easier.  A floor jack helps, one that will support and let you move around the bike.   But any floor style jack that you can brace the engine on is good.

In general, follow the Honda manual's procedure for the small items.  This includes all wiring, hoses and similar things.  A partial list follows:

Drain & remove gas tank.
Remove Radiator Fan & hoses.
Remove Carburetors.
Most wires are removed their closest connector junction in the frame, such as the Oil Sending unit wire and the Alternator wire.
Remove clutch slave by removing the two bolts that hold it on, not by removing the banjo bolt.  This means that you should now be careful NOT to depress the clutch lever.

There are more items to remove in this stage, just be sure to double check with the manual.

Now that all the little stuff is removed, start on the big stuff, not outlined in the manual, to facilitate removing the frame from the engine.  Make sure that the bike is firmly supported by the engine!

Remove the rear wheel and the gear housing.
Slip out the driveshaft.   It may need to be jarred slightly with a soft rubber mallet.
Remove the front forks as an assembly.  First   remove the front brake lever assembly, by removing the two allen bolts that hold it on.  Make sure that the lever assembly is free to travel past the headlight arm.  Since I have the Pichler fairing, I do not have the stock headlight, and I don't remember whether the brake line runs under or over that assembly.  I will update the site when I verify this.  Do not remove the fork brace, or anything else.  Once the brake lever assembly is removed, loosen the four allen bolts holding the fork tubes to the triple clamp.  Slide the forks down, remove the circular clips, then slide the forks the rest of the way out.  Obviously, you will need a jack that goes high enough to do this, or things will get tricky.

Remove the 'cross brace right side frame member' on the left side of the engine.  Once this is completely removed, the only thing holding the frame to the engine will be the top rear engine mount.   Brace the frame and gently remove this bolt.  Now there will be nothing connecting the engine and the frame, so just lift the frame up and rearward.  It should pull right off!