The cost to replace it is not worth it to me, and DIY seems needlessly complex. For now I'll just carry a charger/powerbank - but I'd far rather swap out the battery.
Years ago I had a Dell Streak which I loved - that battery was swappable for that, I'd carry a couple of spare batteries in my bag for it - so I could do 2 or 3 days heavy use, without the need to recharge (the batteries were smaller and lighter than carrying a charger and the weird proprietary cable).