If you need a pliers then they are still gunned up. The actual mechanism for insertion and ejection can not be aligned. Remove the mechanical cage (pretty easy to do) and soak it in WD40 or the like. Then clean and re-grease. Only then would I re-align the heads.

As mentioned caps could be an issue. But I myself have never needed to re-cap a 400k drive. If you do, have fun. Lots of caps on the internal board around the speed motor. If you have the remove that board just tap on the underside where the motor is "pressed" in. Its soldered to the board but does lift out.