I agree with Sofana's comments regarding DIY kits. At least one, possibly both, those kits include the must-have trifecta of (1) well written instructions, (2) plier-type clamps and pressure bands, and (3) either already-placed or clearly indicated placement of the bridge. You can do it, and when you're finished, the result will be highly satisfying. You can find kits online at prices as low as US $29.00 but as always, you'll get what you pay for.
I do not recommend that you paint yours as garishly as I did (see my avatar).
You should repurpose the kit strings to hang pictures or for some other non-musical purpose and instead install name-brand strings labeled as fluorocarbon or Nylgut and buy a 2nd set to have on hand.
Last of all, and weeks after the strings have stopped stretching, you'll need to do a bit of setup consisting of sanding/ filing to get the string action just right. There is lots of good guidance here in UU on that subject. I recently accomplished the necessary nut deepening & adjustment with a US $5.00 set of needle files which you can find at any home improvement store. They're much pricier online or at craft stores but for the purpose of setting up one single DIY uke, I'm not sure why you'd spend more.
Cheers!