There is a crosswalk between the various Census coding schemes and OCC2010 available at this page. The second to last bullet point gives a link to the file.
There are also crosswalk between the ACS occupation codes and OCCSOC on that page (which is a short step to SOC). You can combine the three crosswalks to make a link between the OCC2010 variable and the ISCO08 codes. But you might need to make some classification decisions because SOC is the link between the two and it has more detail than either ACS codes or ISCO codes.
In terms of aligning the crosswalks, the simplest approach is to just combine the ISCO08 codes that match to a single OCC2010 code. I’d also recommend checking out the description page for OCC2010, which links to several technical papers that describe the process used to make OCC2010 and OCC1990, which dealt with similar issues to this.