Clear Transaction logs

You can clear the transaction log by using the following command

Dump tran < db_name > to < file_name >
OR
Dump tran < db_name > with truncate_only
OR
Dump tran < db_name > with no_log

Please read the sybase documents for more details.

Note : Dump tran will not work, if your database option is set
to "truncate log on checkpoint".

if still log is not cleared then, either you can kill the process
or can abort the transaction log by using lct_admin command.