Been a long time since

I did much of my own maintenance. But now that I am retired I thought why not?Changing my 2005 Pro XS lower unit lube which I have been having the dealer do. So only two easy questions. 1. Should I replace the washers on both upper and lower oil plugs? (I assume it would not hurt to replace?) 2. When I removed the prop the slip clutch piece stayed on the prop shaft. Does this need to be greased too? It is a 26 Trophy Plus.