I’ll add my experience being an novice with command prompt input, I started with a C partition size of 953.3 GB (only 67.33 GB used) and recovery partition size of 498 MB and failing install of KB503441. After trying disk management and computer management (both ran as admin), I wasn't able to make changes to recovery partition size in anyway but could reduce C partition by 500 MB creating an 5000 MB unallocated partition, but couldn’t find away to transfer that unallocated space to recovery partition with either of those win10 management tools. After looking at command prompt commands offered by others here and the MS offered commands to make needed partition size changes, because of the extent of order/amount of those commands I worried about possibility of making mistakes. So I finally choice to do as others here have suggested and downloaded
MiniTool Partition Wizard Free 12.8 partition wizard (link below), below that is my experience from using that.
Best Free Partition Manager for Windows | MiniTool Partition Wizard Free
After executing the 3.1 MB downloaded file and un-checking other offerings with it, only leaving partition management control still checked, when installed the program only consumes 179 MB of C drive after the 3.1 download file is deleted.
When MiniTool was open I simply highlighted the recovery partition (left click) and then picked Extend Partition from list on left side, that activated popup window with pull down to select drive to remove space from, defaulted to C drive in my case since that was only one with available space. Below that was a slide bar to control amount of space to move, which I could only get down to 1.6 GB (IIRC) without being zero (close enough). Below side bar now showed new size of partition3 (recovery) will be and what new size of partition C will be. Selected OK in that window, the main windows then showed what all partition sizes would be if you select “Apply” at lower left of program. When you hit “apply” it will then move to where you have to authorize a restart of system, during which time you’ll see changes being made on black monitor screen and after that a restart to your normal desktop. Quick check with disk management will confirm the recovery partition was enlarged to selected amount, 1.3 GB in my case (little below the 1.6 it showed) and partition C reduced by same amount.
That entire process from opening of MiniTool and then a successful install of KB503441 after retry took less than 15 minutes (happy camper), time might vary depending of space used of drive removed from which in my case was low. Hope this helps some near my knowledge level of operating systems.