You can remove the shipping instructions also, by setting the profile option "IBE: Use Shipping Instructions" to No.
Be sure you have ibeCCkdBHdrShip.jsp 120.23.12010000.5 or higher for 12.1.3. There is a known issue with this profile option as discussed in -
Unable To Hide Line Level Shipping In iStore (Doc ID 1197124.1)
For 12.0.6 apply Patch 9057898:R12.IBE.A.
To remove/hide any shipping details make customizations to the shipping page ibeCCkdBHdrShip.jsp.
You can modify this jsp to meet your needs -
1. Optionally set "IBE: Use Shipping Instructions" profile to No to remove the shipping instructions field.
2. Modify a copy of the ibeCCkdBHdrShip.jsp file -
Make a backup copy of $OA_HTML/ibeCCkdBHdrShip.jsp (for example, xxx_ibeCCkdBHdrShip.jsp)
Customize your xxx_ibeCCkdBHdrShip.jsp file by removing the code shipmentPriority and message for the IBE_PRMT_SHIP_PRIORITY_COL
3. Compile the custom file
a) cd $FND_TOP/patch/115/bin
b) perl ojspCompile.pl --compile -s xxx_ibeCCkdBHdrShip.jsp
4. Map the custom jsp to STORE_CHKOUT_B2B_SHIP_HEADER template (see Doc ID:1074274.1)
5. Bounce Oacore server and test
References: How to Map Source Files to Templates (Programmatic Access Names) in Oracle iStore? (Doc ID 1074274.1)