1) Place 2 upside-down stairs of any material right next to each other.
2) Place 2 levers on top of placed upside-down stairs.

The levers pop right off. This also works if you try placing 3 upside-down stairs next to each other and placing the levers first on the outer-most two stairs and then place a lever on top of the middle stair. In that case, all three levers would pop off. This was not an issue in Minecraft 1.7.10 and first appeared for me with the snapshots since then and in Minecraft 1.8.