How do I delete attachments on this site?

How do I delete some of my attachments?

If you’re asking how to delete attachments that are stored on the website then you need to go to your profile settings, then at the very bottom of the toolbar on the left side of the screen you will find a miscellaneous section, under it is a attachments link. If you click on the link it will take you to a page displaying all of the attachments that you have uploaded to the forum thus far. You can then start selecting the attachments and then head to bottom of your attachments and click delete attachments.

Also, you should probably post questions like these on the “Blender Artists website support” section instead of off-topic chat.

Moved from “Misc: > Off-topic Chat” to “Support > Blender Artists Website Support”

And Advent Crown has pointed you in the right direction.