Hey bro, congrats on the Dem holding. It's pretty exciting having the prospect of your first batch of fry. Dem fry are super cute too! If the female has been holding for 2-3 weeks then I am pretty sure she is ready to strip.
I have stripped 6 Dems in the past 2 weeks so here's what I do.
1. Take the opportunity to do a water change and drop you water level to 50%. Put some of the water in a shallow-ish, clean container. You want to be able to get at the fish so high sides are awkward, but you don't want the fish jumping out and flopping around your living room either. Choose you container carefully grasshopper :sage:
2. Take out all your rocks and bog wood. I know this sucks, but do it. As ryanjury said, Dems are buggers to catch and you need to remove all hiding places and obstacles to catch them successfully. Plus the more you chase fish around the tank, the more you upset your community. Trust me, this is the fastest and safest way.
3. Catch the fish! (Da!) I use two nets. A big black one and a small white one. They hate the white one and often will find security in the black one. This is also a good time to mention the value of tank dividers. I wish I had one for my bigger tanks. It would certainly make it so much easier to catch fish by sectioning of the mum.
4. Once said fish is caught, place her quickly and carefully in the stripping container. Now you are ready to strip her. I use cotton buds on my Dems as it seems a bit gentler but be aware that they soggy up pretty quick and swell, so have a few on hand. Everyone uses different things, but you want something that will pry her mouth open, not damage her, and not get in the way of the fry swimming out.
5. Gently take the mum in your less dominant hand (I'm a lefty, so it's my right) and hold her just below the water. Make sure you don't damage her pectoral fins so try to have them laying against her side. Then with you other hand, using the toothpick or cotton bud etc. pry her bottom jaw open. You can gently massage her gills to "squeeze" the fry out, but with some patience and the right technique, they normally exit on their own accord.
6. Put mum back in the main tank and place your fry in a fry tank or fry saver. I make my own fry savers out of 2L ice cream containers and just float them in my main tank.
Hope this helps and good luck! :spop: