"It’s likely to be very similar to the SX200IS for which I’ve written disassembly instructions:
Disassembling Canon PowerShot SX200 IS
Canon PowerShot SX200 IS Lens Disassembly
You should be able to take the back off the lens and with it the sensor and focusing lens, and giving you access to the inside face of the last lens in the barrel. But first, try to ascertain just where the dust is, by seeing how an image changes (or not) as you change the focus or the zoom."
