The phrase manually by hand is a redundancy. The adverb manually means by hand, so by hand adds nothing.
Examples
In these examples, the writers could remove either manually or by hand with no loss of meaning:
It is a well known treatment for cellulite and can be conducted manually by hand or specially designed anti-cellulite machines. [Best Cellulite Treatments]
You can separate the worms from the compost manually by hand . . . [Echo Gardening]
Project monitoring and controlling is done either manually by hand and using paper . . . [Bright Hub]
The target pulleys need to be pulled back and forth manually by hand before and after each shot thus making things difficult. [ESPN Star]
