I've done it once years ago without pulling the engine. Can't remember exactly how I did it but I would imagine that I would have removed the distributor cap or entire distributor if it was in the way. Just be sure to mark the location of the rotor and vac pod so that you insert the distributor back in the correct cog or you will put off the timing.

Needle nose pliers or a small flat blade screw driver will get the e-clip off. Have some extras as it might fly off when you pull it out.

Good luck!