No special access issues
The Wavelength is a giant circuit of boulders and access can be different depending on where you are heading. This approach takes you past the Utopia and Pieshop blocs and up to Wavelength proper. From here, it is easy to navigate to the other boulders while still keeping your feet dry (ish).
Park at the layby near Jerry's Roof and walk back down to the Climber's Club hut. From the back of the hut, there is a small path that starts to lead up the hillside. Just over the crest of the hill, a tree can be see in front of you. Touch the tree for dry feet or miss it to head through the bog. From here, follow the vague path up and right to cross the stream and make the last little slog up to Utopia.
For Pieshop, cross the largely broken wall at the back of Utopia and follow the vague path straight up the hillside. Pieshop quickly comes into view as a large roof above you.
For Wavelength, keep heading up the hillside after walking around the Pieshop boulder. Another vague path exists, this distance is not that far or difficult.
The Grooves boulder is best accessed from Wavelength, where you can see it down to the left.
The Meadow is another stage above again, found by following the stream a little further.