You don't. Snails grow to their shells through a thin layer of skin. If you pick them from their shells you may very well kill or injure them.
An exoskelton is the layer on the hermit crabs actual body that they shed when they outgrow it. (similar as how a snake sheds their skin) A shell is that which the hermit crab takes as a home that normally if from snails.
snails use there thin layer of skin to diffuse any organic gasses.
The Bascal Cell Layer, the deepest layer where cells divide to produce new skin cells.
follicle
Epidermis.
Dermis
The layer of skin that protects a snail's organs is called the mantle. The mantle is a significant part of a snail's anatomy, covering its internal organs and secreting the shell in many species. It plays a crucial role in respiration and excretion as well. Additionally, the mantle helps in forming the protective outer layer of the snail's body.
Snails and slugs have similar skin in that both are soft and moist, which helps them retain moisture and facilitates movement. However, snails have a hard shell that covers and protects their bodies, while slugs lack this shell, leading to differences in their skin texture and vulnerability. Both types of gastropods produce mucus to aid in locomotion and prevent desiccation, but their skin adaptations reflect their differing lifestyles.
epidermis
layer, covering, coating, skin, surface, shell
The shell as is has a layer of thin skin !!