I've got two occassion enlargers .1, crocus 66 en 2, Durst 805

The durst is the one I 've bought now. The lamp was broken so I put a ordinary 25 watt in it in attendation of a new original 100 watt .So when I'm using the both on AGFA PREMIUM GLOSSY MC paper the times are incredible long (up to 15 minutes ) and the enlargement is very low in contrast and tones . Very softly ! Shall I need to use filters? or the FILTER system on the durst or is it the paper that is too old ?
Can anybody tell me how I can change the lamp in the durst . Along the notes delivered with the Durst must it be possible to open it above just where the lamp is .I've spend three hours to get the bad lamp out of it .
I had to screw the system that hold the lamp and the mirror before the lamp out of the Durst head. What is happening if I use a LED lamp in it ? To little light too?

Thanks for helping me