Here's the Monster - General Treyf in new footage
Once the Wind Rangers morph then at the end of their morph sequences is when it's the start of Sentai footage.
New footage
Back to Sentai 

This shot of the Sky is when it goes to new footage
After further review, these shots   are Sentai footage.
This is new footage
New footage of Treyf  
The footage of the 'Ranger Movie' that's seen in widescreen, this shot is when it's the start of Sentai footage.
It's difficult to see the stuff in the movie due to Marah blocking it however that footage in the movie appears to be new footage in this shot
Back to Sentai
Once you see General Treyf's Sword then that's another start of Sentai footage.
Here's the Rangers in new footage after the Storm Striker's Blast has struck Treyf and he's in the middle of his destructive explosion fun This victory pose had to be reshot because Treyf came from Hurricanger 7 and after he was destroyed, the Thunder Rangers ninja streaked into the scene and ninja streak attack the 3 Rangers.
The sequence of Treyf growing is new.
New footage of Giant Treyf
Once you see the zords then that is when it goes back to Sentai footage.
They hadded the Ram Hammer and Turtle Mace into the fight. Originally the Serpent Sword Triple Strike Finisher is what finished off Treyf in Sentai.
As you can see, if you pause the episode just right, when the Mace is about to hit Treyf, you can see this which isn't Treyf at all but is in reality, that monster was Amphibidor.
All zord footage is Sentai footage.