How can alkali metals form covalent bonds? Alkali metals have spherical outer s orbitals unlike elements like carbon which have protruding p orbitals that can "attach" onto other orbitals to form covalent compounds. Even in cases like methane elements like carbon can form hybrid orbitals that still have a protruding p like character.

So how can covalent alkali metals form covalent bonds given that their orbitals are spherical and not protruding?

Does the s orbital distort to be more p like in covalent compounds?

Can the s orbital hybridize and steal a more protruding like character from internal orbitals or from the orbitals of another atom?
For the most part, they don't. 
However, lithium sometimes can. This is due to their valence shells being relatively close to the nucleus, so they have some electronegativity and can form somewhat covalent bonds. 

For more info see this.