I got permission to post this and I think it could help some with birds that bite. :) Kim Gentle Beak technique works like this .... The first thing you have to do is get the bird to associate the words "Gentle Beak" with a gentle touch to (or from) the beak. How I did this was to very slowly...
There is also Positive Reinforcement Training. Getting some praise and a reward like a treat, a toy or some scritches for good behavior are usually great motivations for a bird. If you reward desired behavior with a treat and/or praise and ignore bad behavior, you will establish boundaries that your bird will come to understand. If your bird starts to bite you, give them a toy, so it will attack it instead of your hand. When your bird stops biting you and starts biting the toy, be sure to praise them and give them a treat. If you reward your bird with something they love when they are good, your bird will less likely resort to bad behavior to get your attention. Whenever Cleopatra would bite me and then start screaming, I would walk away from her until I made sure that she had completely calmed down and being good again, then, I would go back to her, praise her and give her a favorite treat. I found this was such an easy way to train my bird. I found by just giving her some space, she would settle down faster making it a less stressful and a more effective way to train her. Whenever she did anything good, I gave her BIG praises and a treat - by continuing to do this, the biting lessened because she was enjoying the rewards. Your bird must get something out of it for this to work, that is why it is important to give a reward of some kind. Try not to react to bad behavior because if you give your bird a lot of attention when they are biting you or misbehaving badly, they will continue to misbehave to get the attention they are craving and the bad behavior will continue.
Gentle Beak is a great way to go about helping your bird to settle down. You have to have plenty of patience and a calm voice. Your p'lett is 8 weeks old? How long have you had him? He/she is just a baby and will experiment biting things. Plus, a parrotlet can be a nipper! They are a parrot. Once you have bonded well with your little one, he will calm down a little bit, but there is no guarantee that he will stop biting altogether. Give him plenty of chew type toys and foraging toys. Paper towels all wadded up may give him some shredding time.