How to update group no incremental by 1 based on every group from 1 to

Question

I work on SQL server 2012 I face issue i can't update group no to every steps from 1 to 3

meaning i need every group from 1 to 3 take identity number incremental by 1 as 1,2,3 etc ..

create table #Replacement
(
PartIDC INT,
PartIDX INT,
FlagStatus nvarchar(50),
HasReplacement nvarchar(50),
groupId int,
step tinyint
)
insert into #Replacement (PartIDC,PartIDX,FlagStatus,HasReplacement,groupId,step)
values

(1222,  3421,   'Invalid',  'Critical', NULL,   1),
(3421,  6421,   'Valid' , 'Active' , NULL,  2),
(1222,  6421,   'Valid' , 'Chain',  NULL,   3),
(5643,  2243,   'Invalid',  'Critical', NULL,   1),
(2243,  3491,   'Valid' , 'Active', NULL,   2),
(5643,  3491,   'Valid' , 'Chain',  NULL,   3)

select * from #Replacement

Expected result

PartIDC PartIDX FlagStatus  HasReplacement  GroupNo Steps
1222    3421    Invalid       Critical           1   1
3421    6421    Valid          Active            1   2
1222    6421    Valid          Chain             1   3
5643    2243    Invalid        Critical          2   1
2243    3491    Valid          Active            2   2
5643    3491    Valid          Chain             2   3

5643    3491    Valid   Chain   2   3

always step 1 and step 3 are both equal on PartIDC

always step 1 and step 2 are both equal on PartIDx from step 1 equal to PartIDC from step 2 .

so How to do Expected result above by update statement to groupId ?