Hi,
You can add the lines by overriding the view "checkout | login" and adding your special content.
The link that you have to use should be the link you have in our Joomla login menu, because HikaShop won't manage the special parameters for "forgot password" or "forgot username". So it should point to the Joomla login menu to be processed correctly.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.