Before removing the cover, make sure to first remove the cover for the cocking mechanism. The top half is freely removable.
The other half of the cocking mechanism is connected with a spring which may slide off the blaster. Be advised this is normal but worth watching to avoid damaging the spring.
At this time, remove the blaster cover to reveal its internals.
If the blaster is resting on its side, the barrel may shift slightly as it is leaning on itself (seen in the image). This is normal but should be handled with care to keep the blaster together.