due to a cat-oil-spill incident this afternoon, I changed my oil but forgot to
change out the oil filter....

should I drain the oil out again and change the oil filter? or will the filter be fine for another 3000~4000 miles?

or is there a way to take out the oil filter without draining the oil first?

thanks in advance!

 

Just change your oil filter... you'll have to add another half a quart of so of oil. But you should be fine.

 

only half a quart? that's not bad.... I had mistakenly thought that taking
out the oil filter would drain most of the engine oil out...

 

The oil filter is usually at a higher location than the oil pan. I'll be impressed if you can drain all your oil through the oil filter hole

 

I change my LS400' s oil filter every 6250 miles.
Engine Oil every 3125 miles.
But it’s recommended to change Oil filter on each engine oil change.