Just using the tooth pick or other sharp implement, scrap plastic cut on an angle, can be enough. Definitely NO THINNERS, as it can melt the plastic. Cutting polish may also be an option, a little harder to control though.
Also noticed it appears you are missing the cocking lever (charging handle) off your blaster, although not mentioned in the CRL it is a requirement
A few options, if you have (or know anyone with) a 3D printer you could print one, some great files here
Or if you have old skool talents (hands on building) you could make one, I have used a plastic paint brush handle, shape and apply a little heat
Or you may be able to purchase one from one of the blaster suppliers
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