Mobile:
Click More in bottom right corner
Click Vendors
Select Vendor to edit
Click Edit in top right corner
Edit Vendor details:
Name
Pictures
Description
Email Address
Phone Number
Click Update in top right corner
Web:
Go to Vendors tab
Select Vendor to edit
Click Edit in top right corner
Edit Vendor details:
Name
Pictures
Description
Email Address
Phone Number
Attach additional files
Click Update in bottom right corner