1. Remove the old tire from the wheelbarrow by removing one or both axle brackets firstly.
2. Measure the hub length of the old wheel. Calculate the length of spacers which would be needed.
3. Measure the diameter of the axle for the existing axle. If the axle is too big, then check the enclosed 3/4" bearings.
4. If the 3/4" bearings fit then remove the 5/8" bearings, with the help of a screwdriver or other tools to pound it out.
5. Insert the new suitable bearing by placing a block of wood on top of it and then hitting the block by a hammer (the block would protect the bearing).
6. Install the new tire onto the wheelbarrow. Install axle through hub, add spacers (if necessary) and finally install it into the axle brackets.