This is a Kerria japonica.

This is Kerria japonica...

... are you able to take several cuttings which don't have flowers on ? Then you would have more chances at being successful.. cut just below where it joins to another shoot ... put them into the compost as soon as cut, or they will probably die ...

Cuttings usually do best pushed in around the edge (sides) of the pot .. keep the compost damp ... put some grit on top of the compost ... don't put in hot sunshine ...

I'm sure others will give you more advice, but I hope this helps :o)

I've been successful making cuttings of Kerria japonica..
I have lots flowering in a pot at the moment !

Kerria alkso spreads by putting up multiple new shoots at the base. You will probably be able to pull one off which already has roots otherwise follow Terratoonies advice

Has mentioned before you can dig down and get a decent clump, water well though at this time of year, can be a little tough to divide, i use a sturdy Mathook. julien.

Is this a plant in your garden Oldcrock if so as soon as flowering is over cut the flowering stems down to the ground. You will then get a myriad of new stems. If you pull one gently you will get a rooted stem. Plant that and next year you will have flowers. Early in the year we take softwood cuttings. Usually round about the end of May. These are taken from the tips of the shrub branches which have grown this year. If you take them too early they will wilt but if you leave them on the growing plant till the end of May they will be stronger and stiffer. You need to plant these soft wood cuttings as quickly as possible because they will wilt very easily. I usually prepare my 6" pot of gritty compost and take a plastic bag to the shrub I am going to propagate. I take maybe 10 cuttings about 4" long from the tip of a branch and pop it in my bag. I take the cuttings back to the greenhouse and doing one cutting at a time I strip off the leaves for 2/3rds of its length. If there are flowers on the cutting they must be removed to give the cutting a chance to put all of its energy in to making new roots. I use an old screw driver to make a hole quite close to the edge of the pot. I pop the cutting in to water then in to my rooting powder for approximately 1/2" from the bottom then pop it in the hole I made for the whole 2/3 length which I stripped. I leave 1" between cuttings and go round the pot until I have no more space left. The reason I only put the cuttings at the edge of the pot is so that they are stimulated to produce more roots as soon as they come up against the barrier of the side of the pot. Water the pot well and let it drain. Use the plastic bag to make a tent over the pot and secure with an elastic band or a piece of string. Leave the pot out of bright sunlight for the first week to 10 days. You should see new growth from the cutting very quickly. if any of the cuttings keel over remove them immediately. I hope this is helpful.