can't install new driver, cannot unload module

it is said that ‘An NVIDIA kernel module ‘nvidia-uvm’ appears to already be loaded in your kernel.’
i tried to unload but ‘operation is not permitted’ (in su mode)

the lsmod | grep nvidia output is

nvidia_drm 45056 0
drm_kms_helper 151552 1 nvidia_drm
drm 352256 3 nvidia_drm,drm_kms_helper
nvidia_modeset 790528 1 nvidia_drm
nvidia_uvm 647168 0
nvidia 12304384 2 nvidia_modeset,nvidia_uvm

im am using centos 7, running on virtual machine. i cant restart server. since every one use the same server

the problem started when i accidentally install new nvidia driver while installing cuda.
i cant do nvidia-smi

i already uninstall cuda and nvidia.

but i cannot install new driver

what should i do