How to ruin a movie name by changing one letter

[Ming the Merciless]

Allen

 

[Ming the Merciless]

Blair Twitch

 

[Ming the Merciless]

The Crop

 

[Ming the Merciless]

Dr Not

 

[Ming the Merciless]

Duet

 

[Ming the Merciless]

Sars Attacks

 

[Sharky]

Moldfinger

 

[lazybloke]

Planet of the ales
Jurassic pork
Rear Widow
How the vest was worn
Gentlemen prefer blinds
Vestworld
Logan's Rum
Close encounters of the Thora Hird kind (I know more than 1 letter)
The Geordie sci fi film "Toon"

If you going to change more than one letter and don't mind being anatomical

Spoiler

Mr Holland's Anus

 

[Dirk]

Tropic Chunder

 

[Drago]

30

Coldfinger

Stab Wars

The Longest Dan

Where Beagles Dare

The Ipcress Bike

Ice Statin Zebra

High Plains Grifter

The Omega Ma

Dan of the Triffids

 

[Ming the Merciless]

Germinator

 

[Ming the Merciless]

Ron

 

[Ming the Merciless]

Wayne‘s Wold

 

[DRM]

Sh*tty Sh*tty bang bang
Mary ploppins

 

[DRM]

Chariots of wire
Top Bun
Brave Fart
The Hunt for Fred October
Sad Max
Dutch Cassidy & the Bun dance Kid
Young Guts
Harry Potter & the Philosophers Phone
The Godfarter
Snow White & the Seven Barfs
Raging Dull
Some like it shot
Singin in the drain
Forrest Dump
Reservoir logs
Brain Spotting
Schindlers Lift
Apocolypse Cow
Jurassic Lark