OJS 2.8 Full Text View, PDF link

We are still using OJS 2.8.x and we are planning to upgrade later this year. We get many complain that the FULL-TEXT view link is too small and often missed out. Is there any way we can put a big PDF Logo instead of the text link there to secure this issue, please?

The word PDF under FULL TEXT is linked, looking to replace it with a PDF logo, please?