I can see a few people are getting bogged down. Here's my two-penn'orth:
Step 1. Down misprints give a fairly obvious instruction.
Step 2. Result of step 1 applies only to across clues to give another instruction.
Step 3. The third word of the result of step 2 is an abbreviation. The instruction itself can be followed by converting letters to numbers (A=1, B=2, etc.) then back again (1=A, ..., 26=Z, 27=A, 28=B, etc.) yielding another instruction.
Step 4. As far as I can tell, you're supposed to slap quotation marks around the first nine letters of the instruction and figure out for yourself in what order to use them to complete the next instruction.
Step 5. At this point you should have a completed grid and another instruction - note that you should be looking at answer lengths rather than clue numbers to follow it. For the purposes of this instruction treat the centre barred-off square as an across clue with 1 letter that fits between 28A and 29A in the order of clues.
Step 6. You should now know what to draw and, given which letters you used to get that description, where to draw it.
"On and on" indeed. :)