A lot will depend on what is meant by "up on blocks"
If the wheels were removed and blocks placed under the axles, take 3 or 4 jacks.
One jack on the "other" side front corner (Or tong.
2nd at the other rear, Place both jacks under either the tong or a frame rail
raise these hacks just enough to start to take a load, they are really there to keep the Trailr from tipping forward or backward.
Using one or two more jacks SLOWLY lift just enough to remove blocks and apply tires.
When finished with the first side, reverse jacks for the other side.
If the blocks are under the stablizer jack points, Lift tong, (using tong jack (NOTE Tong jack can be one of the jacks in the above process) and remove front blocks.. Lower tong remove rear jacks, Raise tong and attach to tow vehicle, Now remove wheels and replace tires, replace wheels and you good to tow.