Holding tank vent filter

[sluggo]

Look at the new one and see that it's threaded on both ends.  Then turn it leftie loosie to remove and rightie tightie to install. 
Capt. George

thanks, I know that, but if you look at the pic, the forward fitting is almost square (the one aft I could easily see and it was just a hose fitting).  So I guess I can just put my pliers on the square fitting to hold it tight, and start left loosie.  thanks again.