How do I trim 5 characters from a string

select t.LeaderLap,
Hours=case when (passingtime*.0001)/3600 < 10 
then '0' + cast(floor((passingtime*.0001)/3600) as varchar) 
else cast(floor((passingtime*.0001)/3600) as varchar) end,
Minutes=case when (floor(((passingtime*.0001)-((floor((passingtime*.0001)/3600))*3600))/60)) <10 
then '0' + cast((floor(((passingtime*.0001)-((floor((passingtime*.0001)/3600))*3600))/60))as varchar) 
else cast((floor(((passingtime*.0001)-((floor((passingtime*.0001)/3600))*3600))/60))as varchar) end,
Seconds=case when ((passingtime*.0001)-((floor((passingtime*.0001)/3600.0000))*3600.0000)-((floor(((passingtime*.0001)-((floor((passingtime*.0001)/3600.0000))*3600.0000))/60.0000))*60.0000))<10 
then '0' + cast(((passingtime*.0001)-((floor((passingtime*.0001)/3600.0000))*3600.0000)-((floor(((passingtime*.0001)-((floor((passingtime*.0001)/3600.0000))*3600.0000))/60.0000))*60.0000))as varchar)
else cast(((passingtime*.0001)-((floor((passingtime*.0001)/3600.0000))*3600.0000)-((floor(((passingtime*.0001)-((floor((passingtime*.0001)/3600.0000))*3600.0000))/60.0000))*60.0000))as varchar) end,
SecondsTrimed=TRIM(Seconds '.')
FROM passings t
Where
leaderlap>=0
AND decoderid=100
AND deleted=0
AND RunID = (SELECT RunID FROM Runs WHERE Preamble = 'R.I')
 and t.PassingID = ( select min(i.passingid) from passings i where i.leaderLap = t.LeaderLap) 
Order By t.LeaderLap asc