How to separate field partdone to text yes or no or null bas

Question

How to separate field partdone to text yes or no or null based on position ?

I work on SQL server 2012 and have table parts have two field

partId int
PartDone nvarchar(50)


partId    partDone
555444    0012
911877    0221

the length of partDone field is 4 numbers

I need to loop within partDone field

if 0 then no

if 1 then yes

if 2 then null

FinalResult

partId    partDone first  second third  four
555444    0012     no      no     yes   null
911877    0221     no      null   null  yes

this field partDone accept only 0 or 1 or 2

and I need to divide them to yes or no or null based on position of every number

What I have tried:

select partId,partDone from Parts