I just recently bought spark plugs( bosch) from Eurosporttuning.com, and i cant seem to figure out how to change them out. I've done plug changes before but never on a volvo. It looks to me like I may have the wrong new plugs, but i ordered the non turbo "bosch platinum +4 plugs" for a 98 S90, any help with all of this mess is greatly appreciated.

Did you remove the black top cover?
Did you remove the coils to gain access to the plugs?

Umm... Wow i guess my dad and i pulled out something totally different. I pulled off the silver ish metal plate on the left hand side of the oil cap .. im gonna try this again and if i have problems ill be asking again..what are the orange looking plugs for anyways?
thanks for pointing out this dumb problem haha.

Most likely the injectors.
Yes remove the black cover on the top middle of the motor(T-30 screws)
Then remove the coils there is 6 total to get to the plugs. A 10MM screw holds them on.

That was an easy job.... i made it harder then it is... I got it done in 15min hahaha well thanks anyways it runs great and hopefully ill get a little better gas mileage! haha
thanks again tech

Glad all is good with it!!!