For OLSAS, Dal and UNB, I just had to put my LSAC Number into the application. They'll do the search and get the result. Generally you'll have to indicate if you are going to write again, so that the schools know that they should check again for new scores. Some schools may also hold off on assessing your application if they know you have another score coming in.
For Ontario Schools at least, on OLSAS you will have to input your LSAC account number which will send your score to OLSAS who will then proceed to forward the scores to the Ontario School(s) of your choosing. You also have to indicate on OLSAS any future LSAT test dates.