The rear plugs can be a challenge, but very doable. I found that by removing the strut tower brace I could get at the plugs much easier. Slide the shield away from the plug, wear a pair of leather or good mechanics gloves, grab the plug boot and twist and pull. You may damage a plug wire, so be prepared to have to replace them. When you install the plugs, be sure to put some di-electric grease in the boot first.
When you are finished, make certain that no plug wire is touching the wire to the O2 sensor.
1999 SSE. 108K. Cleared Corners, Mobile 1, Energy Suspension endlinks. Ported and Polished LIM, NGK TR-55 Sparkplugs, 180 drilled Intense stat, Flow matched injectors, Intense FWI, Intense PCM, MagnaFlow Cat.