In 4.0, if you wanted to delete a large number of records (in a supported manner), you could either select them in the view of 250 at a time and delete them page by page, or use a custom application or utility to leverage the bulk delete features that were built into CRM, but not visible through the user interface. CRM 2011 changed that for the better.
This morning I was importing a set of updates to CRM online – unfortunately I forgot to turn off a workflow rule that creates an attachment for every update. As a result, I had fifteen thousand unwanted/unnecessary notes. Rather than wasting the day deleting them 250 at a time, I used CRM 2011’s easy (and very fast) bulk delete feature. As a result the deletion job which I guessed would take all morning if I had tried to complete it manually, took only about 3 minutes using a bulk delete job. Nice, eh?
How to launch a Bulk Delete Job
There are a number of ways to initiate a bulk delete job, but the easiest way in my opinion, is to start with an advanced find query that returns *only* the records you want to delete.
From the Results page, save the view, then open the “More Actions” Menu and choose “Bulk Delete” to start the Bulk Delete Wizard
Next Either open the Saved Query you just created, or re-create it here. Be sure it returns *only* the records you want to delete:
You can double-check by clicking on the “Preview Records” button – it will return a view of the records that will be deleted by this Job.
If you’re good with the results, Click “Next” to schedule the job.
In this case, I only want to run the job once, but I could schedule it to run every X number of days, which is potentially useful if you’re logging some events, but do not need to maintain history beyond a certain point, or if you want to periodically (and permanently) remove records that become invalid or stale over time.
And finally confirm. (Last chance to back out.)
Once submitted you can review the progress in the ‘System Jobs’ List – Once the job is complete, the Status Reason will show as “Succeeded”
Good luck – and be careful what that query returns – there’s no “undo” on a bulk delete. 
Hello,
This article is very useful, but how can I use Bulk Deletion to delete some Price List Items from some Price List?
Thanks.