or shift the lower unit into gear and just turn the prop until it slips in (much easier and sure to line up correctly)
if you are talking about something in the midsection out of alignment its not supposed to be so find the cause and fix it or it will rub and wear on the shaft. in the short term put the lower unit in position best as you can and lower the motor to the down position then center the collar and gravity wont make it fall to the side so you can put the lower unit back on.
Thanks for the replies. Talked to J and J in jennings and he told me to put a little grease on a dowel and stick it up to the bushing to make it hold in place while the motor is trimmed, worked like charm. He said 90 percent of the time they stay in place when you drop the LU but he had two this year that did that to him.