I'd say 'watch the video', but they've been taken down, so I'll give you a brief description of the route:
SPindash at the start, keep rolling, jump the spikes, jump onto the 'pier', jump spring and roll down the slope. land on the bottom area, run down the slope, jump onto the raised bit of land halfway down, somersault to break the rock then spindash off the platform. Jump into the tunnel in the wall with the invincibilty at the end, spindash out, jump up the 'quarterpipe', jump on the bouncy block, grab the pole that flings you into the air, then hold right as you land on the speed booster.
Sorry, thats a bit vague, but that's a the best I could explain it..