Not such a hard task to take on and complete, but should you not be confident or hands on with plumbing, then you should always call a professional service like Ashford Plumbers who can fit this type of pump.Advice: Always make sure you have the correct replacement before you start the job.1). Make sure that the power and water supply going to the shower is completely isolated. Note: The power is probably from a 13 amp outlet local to the pump, if so, unplug.Double check these isolations. If fitted, open the drain for the pipework at the pump and release any water left in the pipework. If this is not possible, expect some water to discharge when you disconnect the pump from the pipework. The connections should be of the flexible kind with a push-fitting or possibly a compression type of joint so the new fit should be quite straightforward.2). Before you unbolt the old pump unit from the base, disconnect the electrical cables from their terminals, which are in a junction box on the pump. You must check with an electrical tester that the terminals are dead before you touch them. A voltmeter is the best kind, as the voltage is 240vac and is deadly. Once you are happy, then take the old pump off and you can replace the new unit, doing it in reverse. An Ashford Plumber can carry out work in accordance with current Regulations.Good Ideas: a). Make a sketch of electrical connections colours b). Take a photo to ensure correct re-fit.When Finished:De-isolate the power and water supply if you are happy that all connections are correct and tight. Check the area and the equipment for any water leaks. If there are no flex connections provided there will be a need to modify the pipework to achieve this. During this process you need to take great care not to damage the plastic water connections on the new pump, if there was any soldering required. Be careful not to cross thread any connection.