Removing a shrub from the landscape or garden is more than just cutting back the above-ground foliage. Depending on the species of shrub, cutting it back to the ground may just stimulate the foliage to grow back thicker than ever. And if you plan to replace the uprooted shrub with another plant, you will have to clear the way first. Luckily, the removal of a root ball from a shrub is easier than it sounds--provided you have the right tools.
Cut back the shrub's foliage using lopping shears or a small axe. Your first instinct will be to cut it down as close to the ground as possible. But, if you leave some of the shrub's trunk behind, you can use it as leverage to aid in the removal of the root ball.
Water the soil deeply. Lay a slow-running hose at the base of the shrub for a few hours to wet the shrub's root system. Loosening the soil this way will make the root ball much easier to remove.
Dig a trench around the root ball. The trench should be slightly larger than the circumference of the width of the shrub's former foliage and just as deep as the foliage was tall. The best tool for this job is a mattock, which makes a narrow trench and will easily slice through the shrub's roots. But, if you do not have access to a mattock, a spade is an adequate substitute.
Remove the root ball. If you have dug and watered deeply enough, this can be as easy as rocking the root ball back and forth by pushing and pulling on the stump or using your spade or mattock for leverage. If the root ball is stuck fast, use a shovel to undercut the root system. Then try rocking it free again.
Fill the hole left by the root ball with a commercial garden soil. If the shrub was healthy when it was uprooted, chop it up into 1 or 2 inches pieces and toss it on the compost pile. If it was diseased or infested, throw it away.