Yes, you can lower them. The intake, the thing with the strainer that sucks the water in, should come with little extensions that let you lower it.
For the output you will have to rig something up. I don't have a sunsun on hand but basically you just need to lower the output below the water level. You could use a piece of appropriate size
PVC pipe that you could find at home depot. You would just need to figure out how to stick it together. It is very low pressure so as long is it doesn't leak or fall apart you should be fine.