I need to replace the starter solenoid on my 1982 380SL and ran into difficulty while trying to remove the starter.

I assume the starter needs to be removed in order to replace the solenoid but I cannot reach one of the two starter bolts. The lower bolt can be removed from underneath the car but the top bolt seems to be a real pain using standard tools under a jack stand. I removed the lower bolt and learned it is not standard, requiring a hex tool.

Can someone with starter removal experience provide some advice? Is there a special tool needed, or should something be removed to get access from the top?

Thanks.