Download the OpenCart 1.5 extension for Paylike. Upload the zip-file in your OpenCart 1.5 backend (see how to upload an extension here).github.com/paylike/plugin-opencart-1.5/archive/master.zip
Browse to the Paylike extension and install it.
Get the public key and app key from the Paylike dashboard.
Insert them in the fields “Live Mode Public Key” and “Live Mode App Key” on the settings page and enable the extension.
If you wish to do test transactions first, use your Paylike test account's public key and app key and change the “Transaction mode” to “Test”.
Your customers can choose Paylike as a payment method in the checkout.
For the OpenCart 1.5 module to work vQmod is required. If it is not installed, read how to here.