Atlanteans
Create an Atlantean as you would a human, with the single exception that all Nanotech System skills are invariably at 100% and Mind has a minimum of 50.

Greys
If the maximum Body for an average human is, as suggested during UA character creation, 70, the maximum for a Grey is 55. Similarly, no Grey may have greater than 85 Body without specific scientific intervention. However, if the minimum Mind for an average human is, as suggested, 30, the minimum for a Grey is 45; equivalent maximum might be 85.
All Greys have the Greater Psychic skill at equal to their Mind stat, permitting them to have high ratings in those disciplines available to them.

Saurians
As with the Greys, but substitute Soul for Body and Body for Mind. Note also that Saurians may have over 100 Body; in some campaigns, indeed, they are quite likely to. Saurians will all have a minimum Struggle and Firearms skill of 40, with active soldiers and MiBs likely to have far greater skill levels.
Body Morphing should be adjudicated by the GM based on the notes in Exodus, p 87-88