The following steps can be used to remove an Import job that hangs.
1) Stop the Data Importer Service
2) Note down the Job ID of Import that got hanged
3) Connect to MDB and execute below mentioned query based on your requirement.
To delete the Job, update the status to Failed => Update al_import_schedule set status = 2 where [import_schedule_id ] = '<Job_ID>'
To Reprocess the job, update the status to Ready => Update al_import_schedule set status = 0 where [import_schedule_id ] = '<Job_ID>'
4) Delete the Job if you want to from Import Jobs page, then Start the Data Import Service