No tools required to remove the sprocket carrier. They can be a little tight, but once the wheel is off, just lay it brake side down and the sprocket carrier pulls off, work it back and forth and lift it off. Hint: put the sprocket back on for better leverage. If you use an offset front sprocket be sure to use the front sprocket cover from the 78' engine. The K7/K8/F2 were different to accommodate the extra 10mm outboard length of the output shaft:
I have attached some picts of both an early sprocket cover and a late sprocket cover. The most notable differences are at the top rear at both the opening for the chain itself as well as the depth of the upper mounting screw boss. You will also notice the early cover has what appears to be an extra "guide" post cast on the inside of the cover. I have never seen this extra "guide post" on a later model, but there may be early models that might not have it, so don't use that as the only identifier... be sure to measure too! Notice how the one screw boss recess is cutout from the outside face on the later model.
Early cover dimensions:
And the later cover:
Hope that helps!